7(x - 3) + 3(4 - x) = -8
7x - 21 + 12 - 3x = -8
7x - 3x = -8 + 21 - 12
4x = 1
x = 1/4
Okay so if he serves 18 customers in 42 minutes divide 18 by 42 and you get the amount of customers he serves per min which is 0.42857413 then multiply that by 120 since 2 hours add up to 120 minutes and you get 51.43
X= number of dimes
x+6= number of quarters
5(x+6)= number of nickels
$5.40= 540 cents
Add the number of each coin and set it equal to the total in cents.
x + (x + 6) + 5(x + 6)= $5.40
multiply 5 by parentheses; change dollar total to cents
x + (x + 6) + (5 * x) + (5 * 6)= 540
x + (x + 6) + 5x + 30= 540
combine like terms
7x + 36= 540
subtract 36 from both sides
7x= 504
divide both sides by 7
x= 72 dimes
x + 6= 78 quarters
5(x + 6)= 390 nickels
CHECK
72 + 78 + 390= 540
540= 540
ANSWER: There are 72 dimes, 78 quarters and 390 nickels.
Hope this helps! :)
Answer:
I think it's B
Step-by-step explanation:
x = -2
2 + x > -8
2 + -2 > -8
0 > -8
10.5 hours
let t be time then distance travelled by both is
Mr Burges ⇔ d = 50t ( distance = speed × time )
Mrs Burges ⇒ d = 70(t - 3)
At the point of overtaking both will have travelled the same distance
equating their distance and solving for t
70(t - 3) = 50t
70t - 210 = 50t ( subtract 50t from both sides )
20t - 210 = 0 ( add 210 to both sides )
20t = 210 ( divide both sides by 20 )
t = 10.5 hours
