If you want to calculate 5*(a-4) - 8*a = 55, you
have to do few steps to get to know the value of the a.
5*a - 20 - 8*a = 55
-3*a = 55 + 20
-3*a = 75 /(-3)
a = - 25
The correct result and the value of the a is -25.
Answer:
(-1, -5)
Step-by-step explanation:
1. We must calculate x, for that we must substitute y, so we have:
5x=9x+4
2. Now we solve the equation.
5x-9x=4
-4x=4
x=-1
3. Now we must calculate y
y=5x
y=5(-1)
y=-5
And the answer is (-1, -5)
Answer:
d. 21
Explanation:
Step 1 - Subtract 13 from both sides
x + 13 = 34
x + 13 - 13 = 34 - 13
x = 21
After 10 years, there will have been 120 deposits. The last one earns 12%/12 = 1% interest, so is mutipied by 1.01. The one before is multiplied by 1.01². Overall, you have the sum of a geometric series of 120 terms with first term 10.10 and common ratio 1.01. That sum is given by the general formula
Sn = a1·(r^n -1)/(r -1)
S120 = 10.10(1.01^120 -1)/(1.01 -1)
S120 = 1010·2.30038689 ≈ 2323
At the end of the 10th year (before the first deposit of the 11th year), the account balance will be
$2,323
