81.
[tex]x \times 1.5 + x \times 2.5 + \frac{x}{2} \times 4 + ( \frac{x}{2} + 1) \times 3 = 78 \\ 4 \times x + 4 \times \frac{x}{2} + 3 \times \frac{x}{2} + 3 = 78 \\ 4 \times x + 7 \times \frac{x}{2} = 75[/tex]
multiply everything with 2
[tex]8 \times x + 7 \times x = 150 \\ 15 \times x = 150 \\ x = \frac{150}{15} \\ x = 10[/tex]
x is the number of 1.50 and 2.50 wrenches he bought. do the calculations for the rest of them
83.
[tex](x + 2)\times \frac{1}{4} + x \times \frac{1}{2} = 11.75 [/tex]
multiply with 4
[tex]x + 2 + 2 \times x = 47 \\ 3 \times x = 47 - 2 \\ 3 \times x = 45 \\ x = \frac{45}{3} \\ x = 15[/tex]
x is the amount of half dollars in the pile of coins. do the calculations for the quarters.
86.
[tex]3 \times x + 2 \times x + x = 24 \\ 6 \times x = 24 \\ x = \frac{24}{6} \\ x = 4[/tex]
x is the amount of peaches cans, do the calculations for the rest.
