Answer:
15
Step-by-step explanation:
Using the formular, Sn = n/2(2a + (n - 1)d)
where, n = 6: Sn = 6/2( -20 + 5(3)) = 3(15 - 20)
∴ Sn = 15
B) 2/1
find a point, you go up 2 and then over 1!
hope this helps, feel free to mark brainliest!!
Answer:
The lines representing these equations intercept at the point (-4,2) on the plane.
Step-by-step explanation:
When we want to find were both lines intercept, we are trying to find a pair of values (x,y) that belongs to both equations, which means that it satisfies both equations at the same time.
Therefore, we can use the second equation that gives us the value of y in terms of x, to substitute for y in the first equation. Then we end up with an equation with a unique unknown, for which we can solve:

Next we use this value we obtained for x (-4) in the same equation we use for substitution in order to find which y value corresponds to this:

Then we have the pair (x,y) that satisfies both equations (-4,2), which is therefore the point on the plane where both lines intercept.
Answer:
x ≈ ±20.086/√(t - 1)
Step-by-step explanation:
ln(t - 1) + ln(x²) = 6
Recall that lnu + lnv = ln(uv). Then
ln(t - 1) + ln(x²) = ln[(t-1)x²] = 6
Take the natural antilogarithm of each side
(t - 1)x² = e⁶
Divide each side by t - 1
x² = e⁶/(t-1)
Take the square root of each side
x = ±e³/√(t - 1)
x ≈ ±20.086/√(t - 1)
Answer:
This means that the cost of 2 heating oil gallons is 14.
Step-by-step explanation:
f(x) = 4x + 6 , where x is the number of heating oil gallons.
And f(x) = 4x + 6 is the equation for the cost of x gallons.
When the number of gallons are 2 then the cost is;
f(2) = 4(2) + 6 = 8 + 6 = 14
This means that the cost of 2 heating oil gallons is 14.