Y=x+5 4x+y=20 Solving system by substitution

1 answer:

3 0

Y = x + 5....so we sub in x + 5 for y in the other equation

4x + y = 20
4x + x + 5 = 20
5x + 5 = 20
5x = 20 - 5
5x = 15
x = 15/5
x = 3

y = x + 5
y = 3 + 5
y = 8

solution is (3,8)

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aniked [119]

Step-by-step explanation:

so we know X= Numbers of Large boxes and Y= Numbers of Small boxes

And we know the large boxes weigh 75 pounds and the small boxes weigh 40 pounds

So I would have to say the the same except you have to flip the inequality sign like this:

75x + 40y

$\geqslant \\$

200

And if that doesnt somehow work and the question is wording it wrong then

My guess for why its wrong us because its not in slope intercept form Although you still can solve for either varible ( x or y) using standard form also.

So to get from standard form to Slope intercept form (y=mx+b) these are the steps:

Ax+by=C

75x + 40y ≤ 200

Turn it into a linear equation.

75x+ 40y =200

In order to go from one form to another, all you have to do is change the order of the given numbers. First you want to move the Ax to the opposite side of the equation, by either adding or subtracting it. At this point your equation will be set up By = -Ax + C. Then you want to divide the B from the By and the rest of the equation. Therefore you will have y = - Ax/B + C/B. This is the same thing as the slope-intercept form, just a few of the letters are different.

40y=-75x+200 first subtract 75x

y=−1.875×+5 then dived every varible (everything) by 40. and you have your Linear eqaution.