Answer:
Congress
Step-by-step explanation:
<span>first, we are going to define variables as the following:
a = 0
a = π/2
n = 4 rectangles
Δx = [ b - a ] / n ------>Δx = [ π/2 - 0 ] / 4 = π/8
right endpoints :
sum( seq( 4 cos(x) * π/8 , x , 0+π/8 , π/2 , π/8 ) ) = 3.163065 underestimate
left endpoints:
sum( seq( 4 cos(x) * π/8 , x , 0 , π/2-(π/8) , π/8 ) ) = 4.733861 overestimate
the reason because the actual estimate by integral as the following:
π/2
∫ 4cos(x) dx = 4
0</span>
-16t^2+400=0
16t^2=400
take square root on both sides.

4t=20
t=20/4
t=5
2(319) +3(264) = 1430
There are 1,430 pages.
-7x - 2y = 19
4x + y = -12
Set y equal to each other (opposite signs are fine and you could also set x equal instead of y)
-7x - 2y = 19
8x + 2y = -76
Add equations together
x = -52
Plug x value into an equation
4(-52) + y = -12
Solve for y
-208 + y = -12
y = 196
Hope this helps! ;)