do you mind rephrasing it in english
will
Answer:
128 feet squared
Step-by-step explanation:
you multiply 4 by 4 to get 16 ,
then you multiply 7 by 4 and get 28,
also multiply 28 by 4 and get 112 ,
finally add 112 and 16 to get 128
Let number of fives = x then number of ones = 3x and number of tens = x - 1
so we can create the equation
x + 3x + x-1 + y = 26 where y = number of twenties
so
5x + y = 27
also we have the equation
5x + 3x + 10(x - 1) + 20y = 120
18x + 20y = 130..................................(1)
5x + y = 27 multiply by -20:-
-100x - 20y = -540..............................(2)
Adding equation (1) and (2)
-82x = -410
x = 5, that is 5 fives
Now plug x = 5 into equation 1:-
18(5) + 20y = 130
20y = 40
y = 2 , that is 2 twenties
So the answer is there are (3x) = 15 ones , 5 fives, 4 tens and 2 twenties
Explanation:
It helps to understand the process of multiplying the binomials. Consider the simple case ...
(x +a)(x +b)
The product is ...
(x +a)(x +b) = x² +(a+b)x + ab
If the <em>constant</em> term (ab) is <em>negative</em>, the signs of (a) and (b) are <em>different</em>.
If the constant term (ab) is <em>positive</em>, the signs of (a) and (b) will both match the sign of the coefficient of the linear term (a+b).
___
Of course, the sum (a+b) will have the sign of the (a) or (b) value with the largest magnitude, so when the signs of (a) and (b) are different, the factor with the largest magnitude will have the sign of (a+b), the x-coefficient.
<u>Example</u>:
x² -x -6
-6 tells you the factors will have different signs. -x tells you the one with the largest magnitude will be negative.
-6 = -6×1 = -3×2 = ... (other factor pairs have a negative factor with a smaller magnitude)
The sums of these factor pairs are -5 and -1. We want the factor pair that has a sum of -1, the coefficient of x in the trinomial.
x² -x -6 = (x -3)(x +2)
