Question

maria bought two plots of land for a total of $120,000.on the first plot,she made a profit of 15%. On the second she lost 10%.Her total profit was $5,500.How much did she pay for each plot.

Answer 1

a + b = 120,000 --> a = 120,000 - b
.15a - .10b = 5,500
.15(120,000 - b) - .10b = 5,500
18,000 - .15b - .10b = 5500
18,000 - .25b = 5500
-.25b = 5500 - 18000
-.25b = - 12,500
b = 50,000

a + b = 120,000
a + 50,000 = 120,000
a = 120,000 - 50,000
a = 70,000

check..
.15a - .10b = 5500
.15(70,000) - .10(50,000) = 5500
10,500 - 5000 = 5500
5500 = 5500 (correct)

I have no idea if I did this correctly....you will need a second opinion.

Answer 2

Plot 1: cost = x; profit 15% of x = 0.15x
Plot 2: cost = y; loss = 10% of y = 0.1y

Total cost: x + y = 120,000
Total profit: 0.15x - 0.1y = 5,500

Solve the two eqautions as a system of equations.

Answer 3

@kelliegirl33 wrote "I have no idea if I did this correctly....you will need a second opinion."
Don't sell yourself short. You did a great job, and your answer is correct.

Answer 4

thanks....I wasn't even sure if I did it right.....thanks again for confirming

Answer 5

Your check at the end shows you're right.

Answer 6

@mathstudent55 can you also work out yours and let me see

Answer 7

x + y = 120,000
0.15x - 0.1y = 5,500

Multiply second equation by 10 and write it under the first equation:
x + y = 120,000
1.5x - y = 55,000
Add the equations together:
2.5x = 175,000
Divide both sides by 2.5:
x = 70,000
Substitute x in first equation and solve for y:
70,000 + y = 120,000
Subtract 70,000 from both sides:
y = 50,000
Answer: She paid $50,000 for the first plot and $70,000 for the second plot.

Answer 8

THANKS SO MUCH.U GUD

Answer 9

You're welcome