<span>y = –2x + 5
–5y = 10x + 20
replace </span>y = –2x + 5 into –5y = 10x + 20
–5( –2x + 5 ) = 10x + 20
10x - 25 = 10x + 20
-25 = 20...can't be...
answer is <span>D. no solution</span>
Cary x+7. In 3 yrs x+10
Dan x. In 3 yrs x+3
x+10+x+3=83
2x+13=83
2x=83-13
2x=70
x=70/2
x=35
Cary is 42
Dan is 35
X = # 5 inch stones, y = # 10 inch stones
5x + 10y = 145
y = x + 1
5x + 10(x + 1) = 145
5x + 10x + 10 = 145
15x = 135
x = 135/15
x = 9 <=== 9 five inch stones
y = x + 1
y = 9 + 1
y = 10 <=== 10 ten inch stones
Answer:
It will take 47 months ( 3 years and 11 months)
Step-by-step explanation:
We use the compound interest formula here.
Mathematically;
A = P( 1 + r)^t
Where A is the amount which is 2 times the principal here, so we can call it 2P
P is the lump-sum invested
r is the monthly interest rate given as 1.5% = 1.5/100 = 0.015
t = time , which we want to calculate
Substituting these values, we have;
2P = P(1 + 0.015)^t
divide both sides by P
2 = 1.015^t
Take the log of both sides;
log 2 = log (1.015)^t
log 2 = t log 1.015
t = log2/log1.015
t = 46.55
which is approximately 47 months