<span>9 hamburgers and 3 fries for 24.75 and 6 hamburgers and 4 fries for 19.50 can be represented by
9h + 3f = 24.75 and
6h + 4f = 19.5
Multiply by 4 36h + 12f = 99
and multiply by -3 -18h -12f = -58.5
12f and -12f cancel each other out
36h - 18h = 99 -58.5
18h = 40.5
h = 2.25
hamburgers cost 2.25
9h + 3f = 24.75
9(2.25) + 3f = 24.75
3f = 24.75 - 20.25 = 4.50
f = 150
fries cost 1.50
One hamburger and one fries can be represented by :
h + f
2.25 + 150 = 3.75</span>
Write an expression for 213 increased by d: 
Answer:
Step-by-step explanation:
Combine like terms. Like terms have same variable with same power
a) (2xy + 4x) + (15xy - 5x) = <u>2xy + 15xy</u> +<u> 4x - 5x</u>
= 17xy - x
b) (6a + 4b² - 3) + (3b² - 5) = 6a + <u>4b² + 3b²</u> <u>- 3 - 5 </u>
= 6a + 7b² - 8
c) (4x³ - 3x² +4x) + (8x² - 5x ) = 4x³ <u>- 3x² + 8x²</u> <u>+ 4x - 5x</u>
= 4x³ + 5x² - x
d) (7b - 6a + 9y) - (12b + 5a - 2y) =
In subtraction, add the additive inverse of (12b + 5a - 2y)
additive inverse = - 12b - 5a + 2y
(7b - 6a + 9y) - (12b + 5a - 2y) = 7b - 6a + 9y -12b -5a + 2y
= 7b - 12b -6a - 5a + 9y + 2y
= -5b - 11a + 11y
e) (2x² + 7x - 2 + 9y) - (13x + 4x² + 5 - 6y)
Additive inverse of 13x + 4x² + 5 - 6y = -13x + 4x² - 5 + 6y
(2x² + 7x - 2 + 9y) - (13x + 4x² + 5 - 6y)= 2x² + 7x - 2 + 9y -13x - 4x² -5 +6y
= 2x² - 4x² + 7x -13x -2 - 5 + 9y + 6y
= -2x² - 6x - 7 + 15y
