Without values for the other variables, I assume you're asking for a literal equation.
12y+d=-19y+t
31y+d=t
31y=-d+t
y=(-d+t)/31
3[x+3(4x-5)]=15x-24; x+12x-15=5x-8 (divide both sides by 3); 8x=7 (move all the x's to one side), x=7/8
Answer:
6 problems per hour
Step-by-step explanation:
Total problems = 24
she completed the first 12 problems in 1 hour
The last 12 in 3 hours.
Total time = 1 hour + 3 hours
= 4 hours
unit rate for all 24 problems = total number of problems / total time taken
= 24 problems / 4 hours
= 6 problems per hour
