Anyone please help me. I’m learning about Solving Systems of Equations using substitution Question 1 is {Y=3x

Question

Anyone please help me.

I’m learning about Solving Systems of Equations using substitution

Question 1 is
{Y=3x-2
{Y-3x=4

And question 2 is
{0.8x-0.2y=1.5
{0.1x+1.2y=0.5

I don’t really understand it please help

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RuslanHeatt 3 years 2021-07-25T19:41:49+00:00 1 Answers 9 views 0

Answers ( )

  1. Orla
    0
    2021-07-25T19:43:29+00:00
    Reply

    So the point is to use what y equals to combine the x’s and the numbers.

    So y= 3x-2
    In y-3x=4
    (3x-2)-3x=4
    3x-2-3x=4
    0-2=4
    Hmm either the question is wrong or the set does not exist.

    Q2
    0.8x-0.2y=1.5
    0.1x+1.2y=0.5

    I’ll choose to isolate x from the second equation.

    0.1x+1.2y=0.5
    0.1x=0.5-1.2y
    x=(0.5-1.2y)/0.1
    .5/.1 -1.2/.1
    x=5-12y

    Using this sub into first equation
    0.8(5-12y)-0.2y=1.5
    Distribute
    4-9.6y-0.2y=15
    Combine like terms
    -9.8y=11
    11/-9.8
    y= -1.12

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Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )