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Answer: Choice D. 4x^2 + 20x + 25</h3>
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Explanation:
Perfect square trinomials are in the form (a+b)^2 = a^2+2ab+b^2
So the first and last terms must be perfect squares. The middle term is twice that of the square roots of each first and last term.
Choice D fits the description because 4x^2 = (2x)^2 is the first term, so a = 2x and 25 = 5^2 is the last term meaning b = 5. Note how 2ab = 2*2x*5 = 20x is the middle term.
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(a+b)^2 = a^2+2ab+b^2
(2x+5)^2 = (2x)^2+2*2x*5+5^2
(2x+5)^2 = 4x^2 + 20x + 25
1. Take the two x-axis intersections.
For Q 31 it is:
x = -4 and x = 0
2. Reorganise the previous equations
x +4 = 0 and x = 0
3. Put the x side in brackets
x(x+4)
4. Done
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Q 32
x = -1
x = 5
x + 1 = 0
x - 5 = 0
(x+1)(x-5)
Answer:
- equation: (7x-4) +19 +(10x+3) = 52
- x = 2
- red: 10
- blue: 19
- yellow: 23
Step-by-step explanation:
The equation is based on the relation that the perimeter is equal to the sum of the side lengths.
P = red + blue + yellow
52 = (7x -4) +(19) +(10x +3)
52 = 17x +18 . . . . . . . . . . . . . . simplify
34 = 17x . . . . . . . . . . . . . subtract 18
2 = x . . . . . . . . . . . . divide by 17
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red = 7(2) -4 = 10
blue = 19
yellow = 10(2) +3 = 23
Answer:10
Step-by-step explanation:
