4a + 6b = 10
2a - 4b = 12...multiply by -2
----------------
4a + 6b = 10
-4a + 8b = - 24 (result of multiplying by -2)
------------------add
14b = - 14
b = -14/14
b = -1
2a - 4b = 12
2a - 4(-1) = 12
2a + 4 = 12
2a = 12 - 4
2a = 8
a = 8/2
a = 4
so 12a = 12(4) = 48 <==
Answer:
-16
Step-by-step explanation:
4a+(-8)
4(-2)+(-8)
-8+(-8)
= - 16
A: When you multiply two numbers, their exponents add.
So,

Since 64^1/2 multiplied by itself is 64, then it is the square root of 64.
B: The area is irrational. 7 * √7 is irrational.
B but I'm not as sure though