Thaum ua cov kev ua lej ua haujlwm nrog cov zauv feem yooj yim, lo lus nug dhau los ntawm qhov yuav ua li cas ntxiv lawv los sis rho tawm ntawm ib leeg, yog tias tus lej cais muaj cov lej sib txawv? Nws yog ib qho tsim nyog yuav tsum coj cov zauv feem mus ua ib daim foos dav dav kom nws pom tseeb tias feem twg ntawm cov naj npawb tag nrho raug ntxiv los yog rho tawm. Ntawd yog, nws yog qhov tsim nyog los nqa cov zauv feem rau qhov qis tshaj plaws sib thooj.
Nws yog qhov tsim nyog
- - ntawv;
- - cwj mem los yog xaum;
- - tshuab xam zauv.
Cov Lus Qhia
Kauj ruam 1
Sau tawm qhov piv txwv. Cia hais tias koj xav ntxiv cov feem 2 / a thiab 5 / b. Cov lej twg tuaj yeem siv ua cov tsiaj ntawv. Saib dab tsi yog nyob hauv ntu thiab feem ntawm txhua feem thiab yog tias ib qho ntawm lawv los yog ob qho tib si tuaj yeem raug muab tso tseg. Nws raug nquahu kom ua qhov no nyob rau hauv txhua qhov teeb meem, tsis hais seb qhov tshwm sim ntawm kev nqis tes ua no yog sib thooj lossis tsis. Piv txwv li, yog tias koj xav ntxiv 1/3 thiab 4/6, koj yuav tsum txo qis feem thib ob. Nco ntsoov txoj cai kev cai luv luv. Tus zauv faib thiab tus lej cais yuav tsum tau faib raws tus lej tib lub. Hauv qhov piv txwv muab, lawv tau faib los ntawm 2. Nws hloov tawm tias 4/6 = 2/3, uas yog, nws yog qhov tsim nyog yuav ntxiv 2/3 rau 1/3. Qhov tshwm sim yog ib tug.
Kauj ruam 2
Yog tias cov zauv feem tsis thim, lossis qhov tshwm sim ntawm qhov kev ua no, tau txais cov qias neeg sib txawv, nws yog qhov yuav tsum tau nrhiav ib qho muaj. Nco ntsoov cov cuab yeej ntawm ib feem, raws li uas nws tus nqi tsis hloov yog tias seem sab saud thiab qis dua tau khoo nrog tib tus lej. Tus xov tooj no yog hu ua kev txuam nrog. Nrhiav nws rau cov leb feem 2 / a thiab 5 / b. Hauv qhov no, nws yog qhov yuav tsum tau ua kom sib faib rau cov sib faib ua ke, uas yog, qhov zoo tshaj yuav ntxiv yuav muab sib npaug nrog a * b.
Kauj ruam 3
Xam los ntawm tus lej twg koj xav tau khoo txhua feem ntawm cov ntus kom tau cov lej sib npaug. Rau thawj feem, tus no yuav yog tus lej b, rau tus thib ob, tus naj npawb a. Yog li, txhua feem seem tuaj yeem sawv cev raws li 2 / a = 2b / ab; 5 / b = 5a / ab. Hauv qhov no, koj tuaj yeem pom qhov tawm ntawm qhov sib txawv lossis qhov sib txawv. Tawm m = 2b / ab + 5a / ab = (2b + 5a) / ab. Hauv kev siv tib txoj kev, sib thooj sib cais rau peb lossis ntau dua feem tau pom.
Kauj ruam 4
Txog kev suav qhov yooj yim, feem tsawg feem ntau ua rau cov poob qis tshaj feem cuam tshuam. Nws yog sib npaug ntawm qhov tsawg tshaj plaws ntawm ntau tus lej hauv cov zauv hauv qab ntawm txhua cov ntaub ntawv hauv cov xwm txheej ntawm cov teeb meem ntawm cov zauv feem. Nco ntsoov qhov tsawg tshaj plaws uas nquag tau suav nrog. Nws yog tus lej tsawg tshaj plaws los ntawm txhua tus lej thawj. Txhawm rau ua qhov no, muab txhua tus lej coj los ua zauv tseem ceeb. Txhawm rau xam qhov tsawg tshaj plaws ntawm ntau yam, koj yuav tsum nce lawv. Txhua qhov xwm txheej tseem ceeb yuav tsum tau coj mus ntau zaus thaum nws tshwm sim hauv tus naj npawb uas muaj feem ntau ntawm nws. Piv txwv, yog tias koj yuav tsum pom qhov tsawg tshaj plaws ntawm 10, 16, thiab 26, nthuav lawv raws li hauv qab no. 10 = 2 * 5.16 = 2 * 2 * 2 * 2.26 = 2 * 13. LCM = 5 * 2 * 2 * 2 * 2 * 13 = 1040. Los ntawm cov piv txwv no, koj tuaj yeem pom tias thawj qhov tseem ceeb 2 yuav tsum tau coj kom muaj ntau zaus thaum tus lej 16 tau nthuav dav.
