If I assume that p is supposed to be r, then:
r = 12.5
or
r = 25/2 is improper or 12 & 1/2 is proper
Step-by-step explanation:

Would it help if you wrote it as
?
Then you can cross multiply if you know how to do that.
1*x = (-11)(-3)
x = 33 but what happened to the 2 minus signs?
Remember that a ( - ) times a ( - ) = a plus. The two minus signs become a plus.
Let c represent the weight of cashews and p the weight of pecans.
Then c + 10 = total weight of the nut mixture.
An equation for the value of the mixture follows:
$1.50(10 lb) + $0.75c = (c+10)($1.00)
Solve this equation for c: 15 + .75c = c + 10. Subtract .75c from both sides:
15 = 1c - 0.75c + 10. Then 5=0.25c, and c = 5/0.25, or 20.
Need 20 lb of cashews.
Check: the pecans weigh 10 lb and are worth $1.50 per lb, so the total value of the pecans is $15. The total value of the cashews is (20 lb)($0.75/lb), or $15. Does (20 lb + 10 lb)($1/lb) = $15 + $15? Yes. So c= 20 lb is correct.
Answer:

Step-by-step explanation:
Isolate the variable by dividing each side by factors that don't contain the variable.