80...........................................?
<span>7x/9x = 7/9
hope it helps</span>
Answer:
x = -4, y = -4
Step-by-step explanation:
Normally, if it's allowed, I would use a graphing calculator which basically turns the equations (-2x+y=4) and (y=
x-2) into two straight lines, which represent the line of possible values that can fit into the equations. However, since you want the value of x and y in both equations to be the same, you have to look for the intersection of the two graphs. I use desmos.com/calculator to just type in the equations and the lines would be drawn automatically. By hovering over the equation, I can get the two values of x and y (the first value is for x, and the second one is for y).
Here is the working if you want to work it out by hand: (I'm using algebra for this one)
-2x+y=4 -------------------------------- Equation 1
y=x-2 ---------------------------------- Equation 2
Substitute Equation 2 into Equation 1:
-2x+x-2=4
Simplify:
-1x-2=4
-1x=4+2
-1x=6
1x=-6
x=-6
3x=-6×2
3x=-12
x=-12÷3
x=-4 ------------------------------------ Equation 3
Substitute Equation 3 into Equation 1:
-2(-4)+y=4
Simplify:
8+y=4
y=4-8
y=-4
Thus, x=-4, y=-4
The answer is G. Perpendicular lines have opposite reciprocal slopes
So area is 168 sq ft
That means that length * width = 168 sq ft
Since length = 10 + 2 w
we get (10+2w)(w) = 168
Multiply it out and you get 2w^2 + 10w - 168 = 0
This is a quadratic equation. You can use the formula here, but i'll just tell you the answer
w = -12, or 7
since it can't equal -12 (ever heard of a barn with a length of -12?), you figure out the answer is 7.
If the width is 7, then the length is 10+2(7) = 24.
Have a nice day!
