Answer:
b=2
Step-by-step explanation:
we have
9x+12y=21 -----> equation A
6x+8y=7b ----> equation B
we know that
If the system of equations have an infinite number of solutions then the equation A must be equal to the equation B
Multiply equation B by 1.5 both sides
1.5*[6x+8y[=7b*1.5
9x+12y=10.5b ----> equation C
Compare equation A and equation C
9x+12y=21 -----> equation A
9x+12y=10.5b ----> equation C
For the equations to be equal it must be fulfilled that
21=10.5b
solve for b
b=21/10.5
b=2
B! Would be the answer! Good luck on the test!
Answer:
4
Step-by-step explanation:
-3(4x +3)+4(6x +1)=43
-12x-9 +24x +4 =43
12x - 5=43
12x=43 +5
12x=48
x=48 :12
x=4
Answer:
6x - 6
Step-by-step explanation:
(2x + 6) + (4x - 12) ← remove parenthesis
= 2x + 6 + 4x - 12 ← collect like terms
= (2x + 4x) + (6 - 12)
= 6x + (- 6)
= 6x - 6
