Answer:
2x - 7y = -34.
Step-by-step explanation:
As the line we want is perpendicular to y= -7/2 x + 9 it's slope will be
-1 /(-7/2) = 2/7.
Now we find the point of intersection ofn the 2 given lines:
x + y = 10
3x - 4y = -12
Multiply the first equation by -3:
-3x - 3y = -30
Now add this last equation to the second one:
-7y = -42
y = 6
Plug y = 6 into the first equation:
x + 6 = 10
x = 4.
So the point of intersection is (4, 6) and the equation we want passes through this, so using the point-slope form of straight line we have:
y - 6 = 2/7(x - 4)
7y - 42 = 2(x - 4)
7y - 42 = 2x - 8
2x - 7y = -42 + 8
2x - 7y = -34
<span>3 x (80 - 2) = 3 x 80 - 3 x 2 = 240 - 6 = 234 is your answer
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