Question

I’m confused on this answer anyone know it?

Answer 1

Answer:

$y=\frac{26}{7},\:x=-\frac{15}{7}$

Step-by-step explanation:

$\begin{bmatrix}4x+5y=10\\ -2x+y=8\end{bmatrix}\\\\\begin{bmatrix}-2\cdot \frac{10-5y}{4}+y=8\end{bmatrix}$

$-5+\frac{7y}{2}=8\\\\\mathrm{Multiply\:both\:sides\:by\:}2\\-5\cdot \:2+\frac{7y}{2}\cdot \:2=8\cdot \:2\\-10+7y=16\\y=\frac{26}{7}$

$\mathrm{For\:}x=\frac{10-5y}{4}\\\mathrm{Subsititute\:}y=\frac{26}{7}\\x=\frac{10-5\cdot \frac{26}{7}}{4}$

$x=-\frac{15}{7}$