$42.50 divided by 4 is 10.625
Than rounding that up to the nearest hundreds which is the number 2, the total is $10.63.
<h3>The solution as an ordered pair is (x,y) = (2,2)</h3><h3>x = 2 and y = 2 pair up together.</h3>
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Work Shown:
4x+2y = 12
4x+2( y ) = 12
4x+2( 2x-2 ) = 12 ... replace y with 2x-2
4x+2( 2x ) + 2( -2 ) = 12 ... distribution rule
4x+4x-4 = 12
8x-4 = 12
8x-4+4 = 12+4 ... add 4 to both sides
8x = 16
8x/8 = 16/8 ... divide both sides by 8
x = 2 is the first part of the answer
Use x = 2 to find y
y = 2x-2
y = 2(2)-2 ... replace x with 2
y = 4-2
y = 2 is the second part of the answer
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.
