Answer: I think b
Step-by-step explanation: I had the same question
Hello!
To find the surface area of a cube you use the equation

a is a side length
Put in the values you know

Square the number
6 * 121 = 726
The answer is

Hope this helps!
Answer:
The unknown number is 90
Step-by-step explanation:
This question requires a good understanding so as to interprets it well
And always ensure that all symbols used in representation are well stated so as to help the examiner or anyone who will mark it to understand better
So back to the question,let the unknown number be x
And two thirds of the unknown number is 2/3x
2/3x was decreased by 20 which can be written as 2/3x-20
And this decrease gives 40
That's,2/3x-20=40
Then go ahead to solve the question
Start by finding the LCM and the LCM is 3
2x-60/3=40
Cross multiply
2x-60=40×3
2x-60=120
Collect like terms by adding 60 to both sides
2x=180
Divide both sides by 2
x=90
Therefore the final answer is 90
Answer:
39
Step-by-step explanation:
The short answer is 39.
Every triangle has 180 degrees. There are no exceptions to this rule.
Since a triangle has 3 angles, all three together must add up to 180o
A right angle = 90 degrees always.
You are given 51 degrees as your second angle
The third one is x
x + 51 + 90 = 180 Total of three angles must be 180
x + 141 = 180 The left has been added to give 141
x = 180 - 141 Subtract 141 from both sides
x = 39 The third angle = 39