23 can round to 20 and 21 can also round to 20 so all u do is 20x20=400 so 400 is your estimated answer
Answer:
b = 3 and a = -1
Step-by-step explanation:
You have your given equation:
2a - 3b = -11
a + 3b = 8
You need to find what a and b is.
To find b:
2a - 3b = -11
-2a - 6b = -16
I multiplied a + 3b = 8 by -2. When you multiply a number you have to multiply all of them. You have to choose a number that would cancel out all of a.
So now your equation would look like this when you solve for b:
2a - 3b = -11
-2a - 6b = -16
-------------------
a - 9 = -27 then you divide -9 to -27 which is 3 so b = 3.
To find a:
2a - 3b = -11
a + 3b = 8
I multiplied a + 3b = 8 by -1 and 2a - 3b = -11 by -1 as well.
Your equation will look like this when you solve for a:
-2a + 3b = 11
-1a - 3b = -8
------------------
-3a = 3 then divide -3 to 3 which is -1 so a = -1.
Check to see if you have the correct answer by plugging in the number you got for a and b into the equation and solve.
1. 2(-1) -3(3) = -11
-2 - 9 = -11
2. -1 + 3(3) = 8
-1 + 9 = 8
I think it’s 4 m because diameter is 2r
Given:
Compound shape
To find:
The area of the compound shape.
Solution:
The compound shape is splitted into two parallelograms.
<u>Bottom parallelogram:</u>
Base = 7.5 cm
Height = 5 cm
Area of the parallelogram = base × height
= 7.5 × 5
= 37.5 cm²
The area of the Bottom parallelogram 37.5 cm².
<u>Top parallelogram:</u>
Base = 7.5 cm
Height = 4.5 cm
Area of the parallelogram = base × height
= 7.5 × 4.5
= 33.75 cm²
The area of the top parallelogram 33.75 cm².
Compound shape = 37.5 + 33.75
= 71.25 cm²
The area of the compound shape is 71.25 cm².
