If she has 20 dollars and her mom gives her 5 more that would be 25 dollars.
<span>if each gift cost 5 dollars then you would divide 25 by 5 which would come out to 5 gifts. </span>
x = liters of 40% solution
y = liters of 70% solution
Gabe needs 30 liters, so
x + y = 30
Each liter of 40% solution contributes 0.4x liter of acid; each liter of 70% solution contributes 0.7y liter of acid. Gabe needs a solution with concentration 60%, which from 30 liters amounts to a net volume of 0.6*30 = 18 liters of acid. So
0.4x + 0.7y = 18
Solve the system however you like. By substitution, we have
y = 30 - x
0.4x + 0.7(30 - x) = 18
0.4x + 21 - 0.7x = 18
3 = 0.3x
==> x = 10 ==> y = 20
Answer:
cosA + sinA
Step-by-step explanation:
Using trig. identities :
cos(A + B) = cosAcosB - sinAsinB
cos2A = cos²A - sin²A
cos2A = (cosA + sinA)(cosA - sinA)
Therefore, your question is :
=> cos2A/(cosA - sinA)
=> (cosA + sinA)(cosA - sinA)/(cosA - sinA)
=> cosA + sinA
Answer:
40.5
Step-by-step explanation:
12 • 4 = 48
25% of his mom's age is benny's age