Here are all of the answers for the problems showed...
10- 8.72=8.720
13- 2.573<2.753
16- 2.97, 2.714, 2.09, 2.007
Answer:
pretty sure is the first one
Step-by-step explanation:
-1/2x +3 =3x -4
Answer:
b=19
Step-by-step explanation:
2x(3x+5)+3(3x+5)= (3x+5)(2x+3)= 6x²+ 9x+10x+15=6x²+19x +15
6x² + 19x +15 = ax²+bx+c
a=6, b=19, c=15
Answer:
16 lawns
Step-by-step explanation:
set up a proportion:
(4/5 ÷ 1) = (x÷20)
cross-multiply:
5x = 80
x = 16
We are going to make simultaneous equations.
x will be our $3 ice cream and y will be our $5 ice cream
Equation1 ---- x + y = 50 (the sum of all the ice creams they sell)
Equation 2 ---- 3x + 5y = 180 Sum of all the $3 and $5 ice creams is $180
Since we can't solve for both variables we will put one of the variables in terms of the other.
Take x+y=50 and subtract y from both sides. (I could have done subtracted x - it did not matter). Now we have x= ₋ y +50 (negative y +50)
Now I am going to take equation 2 and replace the x with -y +50
3 (-y +50) + 5y = 180
Now I will use the distributive law on the 3 and what's in the parentheses:
-3y + 150 + 5y = 180
Now I will combine like terms (the -3y and the 5y)
2y + 150 = 180
Now subtract 150 from both sides of the equation
2y = 30
Divide both sides by 2
and get y= 15 They sold 15 ice creams that cost $5 each
Since equation 1 is x+y=50 we can replace y with 15
x + 15 = 50 Now subtract 15 from both sides x = 35
Since x represents the $3 ice creams, they sold 35 of those.
Check:
35 X 3 = $105
15 x 5 = + <u>75
</u> $180
