The first 3 are examples of the difference of 2 squares so you use the identity
a^2 - b^2 = (a + b)(a - b)
x^2 - 49 = 0
so (x + 7)(x - 7) = 0
so either x + 7 = 0 or x - 7 = 0
giving x = -7 and 7.
Number 7 reduces to 3x^2 =12, x^2 = 4 so x = +/- 2
Number 8 take out GCf (d) to give
d(d - 2) = 0 so d = 0 , 2
9 and 10 are more difficult to factor
you use the 'ac' method Google it to get more details
2x^2 - 5x + 2
multiply first coefficient by the constant at the end
that is 2 * 2 = 4
Now we want 2 numbers which when multiplied give + 4 and when added give - 5:- -1 and -4 seem promising so we write the equation as:-
2x^2 - 4x - x + 2 = 0
now factor by grouping
2x(x - 2) - 1(x - 2) = 0
(x - 2) is common so
(2x - 1)(x - 2) = 0
and 2x - 1 = 0 or x - 2 = 0 and now you can find x.
The last example is solved in the same way.
x =(-4-√96)/40=(-1-√ 6 )/10= -0.345
:)
Answer:
The length is 72 feet.
Step-by-step explanation:
<em>Equations</em>
2L+2W=192
L=3W
<em>Solving/Substitution</em>
2(3W)+2W=192
8W=192
W=192/8=24
L=24*3=72
The length is 72 feet.
The width is 24 feet.
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Answer: y= 7
Step-by-step explanation:
Answer: 4 tiles
Explanation: if the square has a width of one foot then the length is also one foot since all sides are equal. Therefore 4 squares can fit along a 4 foot wall
