Answer:
(x, y) = (-4, -15)
Step-by-step explanation:
Perhaps you want the solution to ...
y = 3/4x -12
y = -4x -31
Equating the two expressions for y gives ...
3/4x -12 = -4x -31
3/4x = -4x -19 . . . . . add 12
3x = -16x -76 . . . . . multiply by 4
19x = -76 . . . . . . . . . add 16x
x = -76/19 = -4 . . . . divide by 19
y = (3/4)(-4) -12 = -15 . . . . use the first equation to find y
The solution to this system of equations is ...
(x, y) = (-4, -15)
Answer: B
Begin by simplifying the given equation, so it's rearranged into standard form. Move all the terms onto one side, so they equal 0. This would result with -3x-9=0. Quadratic formula is (-b±√(b²-4ac))/(2a). Standard form follow this variable format:
+bx+c. Use the numbers that correspond with each variable to substitute them into the quadratic formula. This would be
(-(-3)±√(-3²-4(4)(-9)/2(4).