Kx-3y=k
y=4x+1 ( we will put it in 1st equation )
kx - 3 (4x+1)=k
kx - 12 x - 3 =k
kx - 12 x = k+3
x(k-12) = k+3
x=

Also y=

We can not divide with zero.
k-12=0
k=12For k= 12 equations have no solutions.
Answer:
the first one is the answer
Step-by-step explanation:
Answer:
-2x² + 90x + 500
Step-by-step explanation:
Use FOIL method
Area of rectangle = length * width
= (50 - x)(2x + 10)
= 50*(2x) + 50*10 + (-x)*2x + (-x)*10
= 100x + 500 - 2x² - 10x
= -2x² + 10<u>0x - 10x </u>+ 500 {Combine like terms}
= -2x² + 90x + 500
The answer is one hundred and twenty