2x + y = 20
-5y = -6x + 12
To use the substitution method, first isolate one of the variables in one of the equations.
Isolate the "y" in the first equation (because it is the easiest to isolate), and substitute it into the second equation:
2x + y = 20 Subtract 2x on both sides
y = 20 - 2x
-5y = -6x + 12 (since y = 20 - 2x, you can substitute 20 - 2x into y)
-5(20 - 2x) = -6x + 12 Multiply -5 into (20 - 2x)
-100 + 10x = -6x +12 Add 100 on both sides
10x = -6x + 112 Add 6x on both sides
16x = 112 Divide 16 on both sides
x = 7
Now that you have found x, you can substitute 7 into x for one of the original equations:
2x + y = 20
2(7) + y = 20
14 + y = 20 Subtract 14 on both sides
y = 6
-5y = -6x + 12
-5y = -6(7) + 12
-5y = -42 + 12
-5y = -30 Divide -5 on both sides
y = 6
x = 7, y = 6
Answer:
The rectangle is 16*18
Step-by-step explanation:
The area of a rectangle is length * width and the perimeter is 2 times length * width
A = l*w
P = 2(l+w)
Replacing A and P
288 = l*w
68 = 2(l+w) => 34 = l+w => 34 - w = l
replacing l in the area
288 = (34 - w) w
w^2 - 34w + 288 = 0
(w - 16)(w - 18)
w = 16
w = 18
replacing in 34 - w = l
you get that when w = 16, l = 18 and when w = 18, l = 16
Answer:
Step-by-step explanation:
The image on the right is not the answer. It is reflected across the y axis. equations and the inverses are reflections of each other across the line y = x. So that lets out the middle one as well which looks to be reflected across y = - x
That only leaves the left image which is the correct answer.
Answer:
D
Step-by-step explanation:
Exponential equation takes the form 
where
- a is the initial value ( a ≠ 0), and
- b is the base ( b ≠ 1)
The equation given in the problem can be written as 
, so it is <em>an exponential equation, </em> where a = -4.8 and b = 4.
Thus we can say that the initial value = -4.8 and the base is 4
The correct answer is D
Answer:
The answer is C I believe
Step-by-step explanation:
