Katrina had a bookcase that holds 200 books. She can put 20 books on each shelf. If 20% of the bookcase is empty, how many shelv
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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
Answer:
y = 120
x = 10.6
Step-by-step explanation:
Given polygons are parallelograms.
In parallelograms, consecutive angles are supplementary which means their sum is equal to 180.
Since two parallelograms are similar:
60 + y = 180 subtract 60 from both sides
y = 120
To find the value of x:
side lengths are proportional because these are similar polygons
cross multiply fractions
18x + 72 = 264 subtract 72 from both sides
18x = 192 divide both sides by 18
x = 10.6 approximately