Question

A system of two equations is shown below. What will you need to multiply the

top equation by in order to solve this system using the elimination method?
X+ y = 4
3x + 4y = 14
O A. 3
B. 4
C. -2
O D. -3

Answer 1

the right answer is : -3

Explanation:

`\left \{ {{x+y=4} \atop {3x+4y=14}} \right. \\\left \{ {{-3(x+y)=-3*4} \atop {3x+4y=14}} \right. \\\left \{ {{-3x-3y=-12} \atop {3x+4y=14}} \right. \\\left \{ {{-3x-3y+3x+4y=2} \atop {3x+4y=14}} \right. \\\left \{ {{-3y+4y=2} \atop {3x+4y=14}} \right. \\\left \{ {{y=2} \atop {3x+4*2=14}} \right. \\\left \{ {{y=2} \atop {3x=14-8=6}} \right. \\\left \{ {{y=2} \atop {x=(6)/(3)=2 }} \right.`