21.
So to solve for the value of a variable in an equation, you would need to isolate x on one side. The first thing you have to do is multiply 2 and (x + 7) together, which can be rewritten as 2(x) + 2(7). After multiplying, your equation would be: 
, or A.
22.
So the rule with multiplying exponents with the same base is to add the exponents together, and the rule with dividing exponents with the same base is to subtract the exponents. Your equation will be simplified as such:
Now the rule with converting negative exponents into fractions is 
. In this case, 4^-2 would turn into 
, or C, which is your final answer.
L = 5 and w = 3
Perimeter = 2(l + w)
P = 2(5 + 3)
P = 2(8)
P = 16 cm
Area = l*w
Area = 5*3
Area = 15 cm^2
Answer:
a) 2a
b) -a + b
c) -b -a
Step-by-step explanation:
a) From C, you just go down with a twice.
b) From A, you go up the a hence -a, then you go down b so -a + b.
c) From B, you go down b to O then you go up a to C.
Answer:
5
Step-by-step explanation:
This is a special right triangle: 5, 12, 13
Or you can solve using the Pythagorean Theorem (a^2+b^2=c^)
--> 13^2-12^2=b^2
-->169-144=b^2
-->25=b^2
b=5
