1.8 - 0.2x = -1.6 Subtract 1.8 on both sides
1.8 - 1.8 - 0.2x = -1.6 - 1.8
-0.2x = -3.4 Divide -0.2 on both sides

x = 17
Answer:
OMG YES THANKS IF U EVER COMMENT ON MY QUESTION I WILL KEEP PUTTING RANDOME STUFF MWAH
Step-by-step explanation:
So hmm notice the picture below
you're simply being asked to, approximate the area, by using 4 rectangles, like in the graph, it doesn't have to be an exact value, just an approximation, based on the width and height of the rectangles, and getting their area by that
those rectangles are 0.39 radian long, since if you split π/2 in 4 pieces, you get around that much, the last rectangle there is a bit smaller than 0.39.... but they don't have to be 4 rectangles of equal length
so, get the area of the rectangles, based on their width and height, and sum them up
<span>f(x) = 1.5 x (1 - x)
f(0.8) = 1.5(0.8)(1 - 0.8) = 0.24
f(0.24) = 1.5(0.24)(1 - 0.24) ~= 0.274
f(0.274) = 1.5(0.274)(1 - 0.274) ~= 0.298
f(0.298) = 1.5(0.298)(1 - 0.298) ~= 0.314
f(0.314) = 1.5(0.314)(1 - 0.314) ~= 0.323
</span>So the answer is D : 0.24, 0.274, 0.298, 0.314, 0.323
The First Answer Should Be 2 Not Four
The Second Answer:
12 : x
4 : 21
Cross Multiply
4x = 252
x = 63