7x-4y=18 4x+20y=27 solve e by elimination method

Question

7x-4y=18
4x+20y=27 solve e by elimination method

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Claire 2 weeks 2021-09-07T22:54:38+00:00 2 Answers 0

Answers ( )

    0
    2021-09-07T22:55:53+00:00

    Answer:

    x=2.14,y=0.75

    Step-by-step explanation:

    7x-4y=18..(1)

    4x+20y=27…(2)

    Multiply (1) by 4

    28x-16y=72…(3)

    Multiply (2) by 7

    28x+140y=189..(4)

    Substrate (3) from (4)

    156y=117

    Divide both sides by 156

    y=117/156

    y=0.75

    Substitute the value of y in (3)

    28x-16(0.75)=72

    28x-12=72

    Add 12 to both sides

    28x=60

    Divide both sides by 28

    x=2.14

    Therefore x=2.14,y=0.75

    0
    2021-09-07T22:55:59+00:00

    Answer:

    x=3

    Step-by-step explanation:

    5(7x-4y=18)

    4x+20y=27

    35x-20y=90

    4x+20y=27                                   just eliminate the -20 and +20 then get

                                                           39x=117

                                                                   

    39x=117

                             then divide on both sides

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45:7+7-4:2-5:5*4+35:2 =? ( )