D- 4 is your correct answer :)
Hope this helps
Answer:
45
Step-by-step explanation:
Since this is only three terms
Find the three terms and add
j=1 3(1)^2+1 = 3+1 =4
j=2 3(2)^2+1 = 3(4)+1 =13
j=3 3(9)^2+1 = 27+1 =28
The sum is 4+13+28 =45
We can find the side length of square 3 by dividing by 4, which is 9.
Then, we find the side length of square 2 by dividing it by 4, which is 12.
To find the AREA of square 1, we do a^2+b^2=c^2. This is basically adding up area of square 1 and square 2 to get square 3.
a^2+b^2=c^2
9^2+12^2=c^2
81+144=225
So the area is 225 units.
Answer:
x = 136/35; y = -⁹/₁₀
Step-by-step explanation:
(1) 7x + 8y = 20
(2) 7x – 2y = 29 Subtract (2) from (1)
10y = -9 Divide each side by 10
(3) y = -⁹/₁₀ Substitute (3) into (1)
7x - 2(-⁹/₁₀) = 29
7x + 18/10 = 29 Subtract 18/10 from each side
7x = 29 - 18/10
7x = (290 - 18)/10
7x = 272/10 Divide each side by 7
x = 272/70
x = 136/35
x = 136/35; y = -⁹/₁₀
Check:
(1) 7(136/35) + 8(-⁹/₁₀) = 20
136/5 - 72/10 = 20
136/5 - 36/5 = 20
100/5 = 20
20 = 20
(2) 7(136/35) – 2(-⁹/₁₀) = 29
136/5 + 18/10 = 29
136/5 + ⁹/₅ = 29
145/5 = 29
29 = 29
