Question

Simpson is solving the systems of equations below by substitution. Show Mr. Simpsons first step if he substitutes the first equation into the second equation. DO

SOLVE!


y = 5x + 12

3y + 4x = 150


I’m struggling on this one.

Answer 1

`x=6,y=42`

Explanation:

The equations are

`y=5x+12`

`3y+4x=150`

Substituting the first equation in the second we get

`3(5x+12)+4x=150`

`\Rightarrow 15x+36+4x=150`

`\Rightarrow x=(150-36)/(19)`

`\Rightarrow x=6`

`y=5x+12=5* 6+12\\\Rightarrow y=42`

So, the required values are
`x=6,y=42`