Answer:
The answer is 4r² – 9
Denise answer is correct.
Step-by-step explanation:
One of the methods of solving the given equation [(2r – 3)(2r + 3)] is the FOIL method
Using the FOIL method (Used for multiplying binomials)
F stands for first
O stands for outer
I stands for inner
L stands for last
In this method, it means we will first multiply the first terms followed by multiplying the outer term, then multiplying the inner terms and finally, the last terms.
So, for the equation (2r – 3)(2r + 3)
First : (2r)(2r) = 4r²
Outer : (2r)(+3) = 6r
Inner : (–3)(2r) = – 6r
Last : (–3)(+3) = – 9
Adding the results we get
4r² + 6r – 6r – 9 (+6r and – 6r cancels out)
= 4r² – 9
∴ (2r – 3)(2r + 3) = 4r² – 9
Hence, Denise answer is correct
Answer:
x = 3
Step-by-step explanation:
You can use cross multiply.
8x = 6 x 4
8x = 24
x = 3
They are vertical angles, and so set them equal to each other
x + 40 = 3x
Isolate the x. Subtract x from both sides
x (-x) + 40 = 3x (-x)
Simplify
40 = 3x - x
40 = 2x
Isolate the x. Divide 2 from both sides
40/2 = 2x/2
x = 40/2
x = 20
20, or (A) is your answer
hope this helps
X= grade on next test
Add up all scores, divide by 6 and this equals the average of 84
(86 + 91 + 86 + 61 + 87 + x)/6= 84
add in parentheses
(411 + x)/6= 84
multiply both sides by 6
411 + x= 504
subtract 411 from both sides
x= 93
ANSWER: 93 is needed on the next test to have an average of 84
Hope this helps! :)
Answer: (58)
Step-by-step explanation:
3(42)+(5)(2)
=(3)(16)+(5)(2)
=48+(5)(2)
=48+10
=58
