The answer is <a is congruent to < d
because you already have <abe = <dbe
Solution:
1) Rewrite it in the form {a}^{2}-2ab+{b}^{2}, where a={d}^{2} and b=4
{({d}^{2})}^{2}-2({d}^{2})(4)+{4}^{2}
2) Use Square of Difference: {(a-b)}^{2}={a}^{2}-2ab+{b}^{2}
{({d}^{2}-4)}^{2}
3) Rewrite {d}^{2}-4 in the form {a}^{2}-{b}^{2} , where a=d and b=2
{({d}^{2}-{2}^{2})}^{2}
4) Use Difference of Squares: {a}^{2}-{b}^{2}=(a+b)(a-b)
{((d+2)(d-2))}^{2}
5) Use Multiplication Distributive Property: {(xy)}^{a}={x}^{a}{y}^{a}
{(d+2)}^{2}{(d-2)}^{2}
Done!
Use simultaneous equations:
2x + 7 = x^2 + 8x - 9
7 = x^2 + 6x - 9
16 = x^2 + 6x
+ or - 4 = 7x
answer is
-4/7 or 4/7
% increase = 100 - 85
--------- * 100
85
= 17.65
= 18 % to nearest per cent
The answer is the first option: 1) 
> the quantity 
times 
minus 
all over 
The explanation is shown below:
1. To solve this problem you must pply the following proccedure:
2. Move the term
to the left member. As the variable is negative, multiply the expression by
and change the direction of the sign:
