Question

3x-2y = -1
у= 4х - 7

Answer 1

3x-2(4x-7)=-1
3x-8x+14=-1
-5x+14=-1
subtract 14 on both sides
-5x=-15
divide -5 on both sides
x=3

Answer 2

x =3

y =5

Explanation:

Solve by substitution

`\begin{bmatrix}3x-2y=-1\\ y=4x-7\end{bmatrix}\\\\\mathrm{Subsititute\:}y=4x-7\\\\\begin{bmatrix}3x-2\left(4x-7\right)=-1\end{bmatrix}\\\\\mathrm{Simplify}\\\begin{bmatrix}-5x+14=-1\end{bmatrix}\\\\\mathrm{Isolate}\:x\:\mathrm{for}\:-5x+14=-1:\quad x=3\\\mathrm{For\:}y=4x-7\\\\\mathrm{Subsititute\:}x=3\\y=4*\:3-7\\\\Simplify\\y=5\\x=3,\:y=5`