Find the product of following:(i) (x+3) (x+2) (ii) (2x-1) (2x-7)
1 answer:
Part (i)
<h3>Answer: x^2 + 5x + 6</h3>-----------------
Work Shown:
(x+3)(x+2)
y(x+2) ..... Let y = x+3
y*x + y*2 ... distribute
x(y) + 2(y)
x(x+3) + 2(x+3) .... plug in y = x+3
x*x + x*3 + 2*x + 2*3 ... distribute
x^2 + 3x + 2x + 6
x^2 + 5x + 6
=====================================================
Part (ii)
<h3>Answer: 4x^2 - 16x + 7</h3>-----------------
Work Shown:
We could follow the same set of steps as shown back in part (i), but I'll show a different approach. Feel free to use the method I used back in part (i) if the visual approach doesn't make sense.
The diagram below is a visual way to organize all the terms. Many textbooks refer to it as "the box method" which helps multiply out any two algebraic expressions.
Each inner cell is found by multiplying the corresponding outer terms. For instance, in the upper left corner we have 2x*2x = 4x^2. The other cells are filled out the same way.
The terms in those four inner cells (gray boxes) are:
- 4x^2
- -14x
- -2x
- 7
The like terms here are -14x and -2x which combine to -16x, since -14+(-2) = -16.
We end up with the answer 4x^2-16x+7
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Answer:
D.) 8
Step-by-step explanation:
You can use the Pythagorean theorem because this is a right triangle:
a and b are the legs and c is the hypotenuse. The hypotenuse is always the longest side in a right triangle (since it is opposite the biggest angle). The two legs squared have to add up to the hypotenuse squared.
Fill in values:
Simplify exponents:
Isolate the variable. Subtract 225 from both sides:
Find the square root of both sides:
The missing leg length is 8.