The sequence:
a 1 = 30, a 2 = 70, a 3 = 110, a 4 = 150, a 5 = 190,...
a 2 = a 1 + d
70 = 30 + d
d = 70 - 30 = 40
a n = a 1 + ( n - 1 ) * d
For the 25th month:
a 25 = 30 + 24 * 40 = 30 + 960 = 990
Answer: B ) 990.
X + y = 12 / x (-45);
Then, -45x - 45y = -540;
We have 80x + 45y = 645 and
-45x - 45y = -540
________________
35x = 105;
Finally, x = 105÷35;
x = 3;
y = 12 - 3;
y = 9;
To find the box to the top left, we can multiple the sides like rectangles. To find the top left box, we can multiply -1 and 0.5y to get -0.5y.
To find the box on the bottom right, we can multiply the sides like rectangles again. To find the bottom right box, we can multiply 24x and 3 to get 72x.