-10x + 5y = 15
Divide everything by 5.
-10x/5 + 5y/5 = 15/5
-2x + y = 3
So, we can imagine some values to this equality
If x = -1 and y = 1 we have
-2.(-1) + 1 = 3
2 + 1 = 3
3 = 3
Another way we can say:
-10x + 5y = 15
5y = 10x + 15
Divide everything by 5.
y = 2x + 3
So just imagine values to x, let's make 0, 1 and 2.
y = 2.0 + 3
y = 0 + 3
y = 3
y = 2.1 + 3
y = 2 + 3
y = 5
y = 2.2 + 3
y = 4 + 3
y = 7
So, when x = 0, y = 3.
When x = 1, y = 5.
When x = 2, y = 7.
Answer:
x=6
Step-by-step explanation:
5x-10=3x+2
5x-3x=2+10
2x=12
Answer:
9.9 years
Step-by-step explanation:
A = P e ^(rt)
Where A is the amount in the account
P is the amount invested
R is the interest rate
t is the time
P = 8500
r =7% = .07
A = 17000
Substituting into the equation
17000=8500 e^(.07t)
Divide each side by 8500
17000/8500=8500/8500 e^(.07t)
2 = e^(.07t)
Take the natural log of each side
ln (2) = ln e^(.07t)
ln(2) = .07t
Divide each side by .07
ln(2)/.07 = .07t/.07
ln(2)/.07 = t
9.902102579=t
Rounding to one decimal place
9.9 years
Sin 3pi/4 is angle 135 degrees or 45 degrees below 180 degrees. Hence it's opposite side is 1 and adjacent is 1, implying the hypothenus is sqrt(2). Hence
Sin 3pi/4 = 1/sqrt(2). Now multiply by sqrt(2)/sqrt(2) to get:
[1/sqrt(2).] * [sqrt(2)/sqrt(2)] = sqrt2)/2