The decimal number is 0.9
(7-11) • (5) = -20
A. (5) • 7 + (5) • (-11)
↳ 35 + (-55)
↳ 35 - 55 = -20
B. -(-7+11) • (5)
↳ -4 • 5 = -20
C. (5) • 7 - (5) • 11
↳ 35 - 55 = -20
D. (7+11) • (5)
↳ 18 • 5 = 90
A B & C are correct
Explanation:
To find x we need to find the unknown side that connects the two triangles using the Pythagorean theorem:
a² + b² = c² (c is always hypotenuse)
So:
a² + 6² = 9²
a² = 9² - 6²
a² = 81 - 36
a² = 45
a = sqrt45
Now we do the same thing for the other triangle:
x² + 5² = sqrt45²
x² + 25 = 45
x² = 20
x = 2√5 or 4.5...
-axis (washer method):
-axis (shell method):
(shell method):
(washer method):