Question

(2x + 7y = -2418x+y=12 solve by substitution​

Answer 1

Answer:

x = .87, or when approximated to a fraction, 27/31

y = -3.67, or when approximated to a fraction, -1287/350

Step-by-step explanation:

Lets start by rewriting out our equations

2x + 7y = -24

18x + y = 12

Lets solve for a y value; the second equation is easiest, as the y value has no coefficient (the number that is multiplied times a variable). To do this, lets move the 18x to the other side. Now our two equations look like:

2x + 7y = -24

y = -18x + 12

Next, lets plus the second equation into the first equation in regards to y.

2x + 7(-18x + 12) = -24

Now, lets solve!

2x -126x + 84 = -24

Then, combine your terms!

-124x = -108

Divide by (-124)!

x = -108/-124

x = 27/31

Now that we know x, lets plug this back in to the first equation to find y!

2(27/31) + 7y = -24

1.74 + 7y = -24

7y = -25.74

y = -3.67, or when approximated to a fraction, -1287/350