Mr. abernathy purchases a selection of wrenches for his shop. his bill was $78. he buys the same number of $1.50 and $2.50 wrenches, and half that many $4 wrenches. the number of $3 wrenches is one more than the number of $4 wrenches. how many of each did he purchase?

He purchased 10 $1.50 and 10 $2.50 wrenches. And 5 $4 wrenches and 6 $3 wrenches.

Step-by-step explanation:

Lets represent the number of $1.50 wrenches by x

The number of $1.50 and $2.50 wrenches are equal. The number of $4 wrenches is x/2 since its half of number of $1.50 wrenches and the number of $3 wrenches is (x/2) +1. So the equation is

x(1.50) + x(2.50) + x/2(4) + ((x/2)+1)(3)=78

1.5x+2.5x+2x+(3x/2)+3=78

6x+(3x/2)=78-3

6x+(3x/2)=75

Multiply through by the LCM

12x+3x=150

15x=150

15x/15=150/15

x=10

Since the number of $1.50 wrenches is x, the number of $1.50 wrenches is 10.

The same applies to $2.50.

$4 is x/2 which is 10/2=5

$3 is (x/2) +1 and x/2 is 10/2 which is 5

so it 5+1=6

$25

step-by-step explanation:

25 - 4.50 = 20.5

20.5 / 2 = 10.25

10.25 + 10 = 20.25

20.25 - 12.50 = 7.75

therefore the answer is $25 as shown as the first number.

the answer is y < -3 or   y > 3

-3y > 7 + 2

-3 y > 9

y < -3