A = (h * b) / 2
A = 200
h = 4b
200 = (b(4b) / 2
200 * 2 = b * 4b
400 = 4b^2
400 / 4 = b^2
100 = b^2
sqrt 100 = b
10 = b ..... base is 10 cm
h = 4b
h = 4(10)
h = 40 <=== height is 40 cm
Answer:

Step-by-step explanation:
1. Combine like terms
2y-7y = -5y
-5y=5
2. Divide by -5 and the answer is 
21x is 21x im glad that I can help you
Answer:
use the reverse Pythagorean therm BC= 4 DE= 4.8
Step-by-step explanation:
The square root of 5(squared) - 3(squared) = 4
the square root of 8(squared) - 6.4(squared) = 4.8
Answer:
Step-by-step explanation:
x² - 144 = x² - 12²
= (x +12)(x - 12)
a² - b² = (a + b)(a-b)