C = # of carpenter hrs , b = # of blacksmith hrs
c + b = 30...c = 30 - b
20c + 25b = 690
20(30 - b) + 25b = 690
600 - 20b + 25b = 690
-20b + 25b = 690 - 600
5b = 90
b = 90/5
b = 18 <== hrs worked as blacksmith
c + b = 30
c + 18 = 30
c = 30 - 18
c = 12 <== hrs worked as carpenter
Answer:
a
Step-by-step explanation:
11-9=2 and 2 times 7 is 14, 14 plus 12 is 26 ,and 26=26 is a true statement
Answer:
i would say A. The initial cost for renting a snowmobile is $75, with each hour of use costing an additional $25.
Step-by-step explanation:
Answer:
N=250
Step-by-step explanation:
"twice as many nickels as dimes" means N =2D [eq1]
"collection of nickels and dimes is worth $25" means
5N + 10D = 2500 [eq2]
(To avoid using decimal points, PLZ express everything in cents.)
Substitution (substitute N from eq1 into eq2]:
5(2D) + 10D = 2500
10D + 10D = 2500
20D = 2500
D = 125
N=2D [eq1 again]
N=2(125)
N=250
Check:
Is 5(250) + 10(125) = 2500 ?
1250 + 1250 = 2500 ?
2500 = 2500 ?yes