Options in 3rd and 4th questions are wrong!. Hope it helps :)
Answer:
783
Step-by-step explanation:
We have to find the sum of Arithmetic series from t = 1 to t = 18 represented by (5t - 4)
The formula to find the sum of an Arithmetic series when first and the last term is known is:

Here,
n = Total number of terms = 18
= First Term = 5(1) - 4 = 1
= 18th Term = 5(18) - 4 = 86
Using the values in the above formula, we get:

Thus, the sum of 18 terms of the given Arithmetic Series is 783.
Answer:
x = 3, y = -4
Explanations:
The given system of linear equations is:

The graph representing the equations is plotted below:

The point where both lines intersect is the solution to the system of equations.
The lines intersect at the point (3, -4), therefore, (3, -4) is the solution to the system of equations
Answer:
1.6
Step-by-step explanation:
The maximum is the greatest number