Sum of infinite series of a GS is a1 / (1-r)
so here it is 65 / (1 - 1/6) = 65 / 5/6 = 65*6 / 5 = 78 answer
Answer:
$9.9
Step-by-step explanation:
Answer:
Step-by-step explanation:
26% is (26-20)/(50-20) = 6/30 = 1/5 of the way between 20% and 50%. That means 1/5 of the solution is 50% acid.
50% acid: 1/5 · 100 mL = 20 mL
20% acid: 100 mL -20 mL = 80 mL
Delbert must mix 80 mL of 20% acid and 20 mL of 50% acid.
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Maybe you'd like to see an equation. Let x represent the amount of 50% acid required. Then 100-x is the amount of 20% acid needed. The amount of acid in the mix is ...
0.50(x) +0.20(100 -x) = 0.26(100)
(0.50 -0.20)x = (0.26 -0.20)100 . . . . subtract 0.20(100)
x = (0.26 -0.20)/(0.50 -0.20)×100 = 20
This last expression should look a lot like the one we started with in this answer. It shows you how you can almost write down the answer to mixture problems without a lot of work.
Answer:
x = 0
y = -12
Step-by-step explanation:
Plug in what y is equal to into the second equation
-3(x - 12) = 2x + 36
Distribute the -3
-3x + 36 = 2x + 36
-36 -36
-3x = 2x
They cannot be equal so x = 0
Plug in 0 into the y equation
y = 0 - 12
y = -12
SA=4pir²
given SA=12.56
12.56=4pir²
divide both sides by 4
3.14=pir²
3.14=3.14r²
divide both sides by 3.14
1=r²
sqrt both sides
1=r
the radius is 1 in
