Answer: 
Step-by-step explanation:
You need to use the following formula that is used to find the area of a trapezoid:

Where "M"and "m" are the bases of the trapezoid and "h" is the height of the trapezoid.
Based on the information given in the exercise, you can identify that:

Knowing these values, you can substitute them into the formula:

Finally, you must evaluate in order to find its area. This is:

Given, the ratio of blocks A, B, C,D are in the ratio 4:7:3:1
Let us consider the common ratio to be ‘x’.
So, toy blocks with alphabet A is 4x and
toy blocks with alphabet B is 7x and
toy blocks with alphabet C is 3x and
toy blocks with alphabet D is x
Again, the number of ‘A’ blocks is 50 more than the number of ‘C’ blocks.
As no. of ‘A’ and ‘C’ blocks are 4x and 3x respectively.
So,
4x=50 + 3x
x=50
Thus, the number of ‘B’ blocks is 7x = 7(50) = 350
350 is the required number.
The correct answer is: 9 + c = 12
Further explanation:
Given
c = number of babies whose eyes are closed
So,
If the total number of babies are 12 then the sum of babies with eyes closed and eyes opened should be equal to 12.
As c is the number of babies with eyes closed and 9 is the number of babies with eyes opened then,

The equation can be used to find the number of babies whose eyes are open

Three babies have their eyes closed in the photograph.
Keywords: Linear equations, Word problems
Learn more about linear equations at:
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Answer:
5
11
8
Step-by-step explanation: