Since it starts at 12 and is increasing by 5 each time, the 70th term will be;
12 + 5(70)
12 + 350
362
362 is the 70th term of the sequence.
Combine like terms
-7y² + 6y² - 2y² = -3y²
4y + (-5y) - (-9y) = 4y - 5y + 9y = 8y
9 + 9 - (-2) = 9 + 9 + 2 = 20
-3y² + 8y + 20 is your answer
hope this helps
Check the picture below.
notice the composite is just,
a 5x2 rectangle.
a triangle(yellow) with a base of 2 and a height of 2.
a triangle(red) with a base of 6 and a height of 4.
get the area of each, sum them up, and that's the area of the composite.
Five is b
Six is a
Seven is a
Goood day now