Try this:
1) note that weight of pure antifreeze before mixing and after mixing is the same. So, if 'x' is weight of pure antifreeze in 50% solution, it is possible to make up equation before mixing: 0.5x+0.2*90.
2) there are 0.2*90=18 gal. of pure antifreeze in the 20% solution. If 'x' gal. is the weight of pure antifreeze in 50% sol. and 18 gal. is the weight of pure antifreeze in 20% sol., it is possible to make up an equation after mixing: 0.4(x+18).
3) using the both parts: 0.5x+0.2*90=0.4(x+18) ⇒ x=54 gal. of <u>pure</u> weight.
4) to find 50% solution of 54 gal. pure weight just 54:0.5=108 gal.
Answer: 108 gal.
3,045 = 210x
3,045/210 = 14.5
A good estimate of the cost would be:
$14.50
For it to be non-linear, the rate of change cannot be constant. For the first table the rate is a constant 1 and the second table has a constant rate of -1. The 3rd and 4th tables have no constant rate and thus are non-linear.
The 4th table is increasing while the 3rd table is decreasing.
So the 3rd table, Set C, is the only non-linear negative association between x and y.
Answer:
1/3x - 3
Step-by-step explanation:
To find the inverse, we exchange x and y and then solve for y
y =3x+9
Exchange x and y
x = 3y+9
Then solve for y
Subtract 9 from each side
x-9 =3y+9-9
x-9 = 3y
Divide by 3
1/3(x-9) = 3y/3
1/3(x-9) = y
Distribute
1/3x-3 = y
The inverse is 1/3 x -3
Answer:
x=-6, y=0
Step-by-step explanation:
Use the 3x-9y=-18 equation and add 9y to both sides to have 3x on its own on the left side. Then, divide by 3 on both sides. Then you'll have x=-6+3y. Plus this back into the 5x+4y=-30 equation and you'll get 5(-6+3y)+4y=-30. Use the distributive property and you'll get -30+15y+4y=-30. Simplify and get -30+19y=-30, then add 30 to both sides and you'll get 19y=0. Divide by 19 on both sides and you'll get y=0. Now that we know y=0, plug that back into the 5x+4y=-30 equation, and you'll get 5x+4(0)=-30. Simplify and you'll get 5x=-30. Divide by 5 on both sides and you'll get x=-6.
