Answer:
43 questions in total
Step-by-step explanation:
the original equation with the unknown (total number of questions on the test) will look like this

we know this because to work out a percentage in the 1st place you need the total ÷ number (in this case it's ÷ how many questions out of the total she did answer)
now you rearrange.
you need to move the 24 to get the total on it's own here's how you do it

what you do to one side of equation you have to do to the other. the 24 and 24 on the left will cancel because 24÷24=1 and we don't write
got mum of Q's x 1= 80 x 24
now you convert % to decimal

replace

now you take the original and + the 19

therefore there are a total of 43 questions on the exam
To solve this problem, we need to first find the dimensions of the side of the blue and purple squares.
We're given that the purple (smaller) square has a side length of x inches.
We are also given that the blue band has a width of 5 inches.
Since the blue band surrounds the purple square on both sides, the length of the blue square is x+2(5)=x+10 inches.
The net area of the band is therefore the difference of the area of the blue square and the purple square, namely take out the area of the purple square from the blue.
Therefore
Area of band

[recall



or 20(x+5) if you wish.
Answer:
Step-by-step explanation:
The coefficients of the x terms are {1, 3, -3}, so the discriminant, b^2 - 4ac, is 3^2 - 4(1)(-3), or 9 + 12, or 21. The positive nature of the discriminant tells us that there are two real, unequal roots. Following the quadratic formula, we get:
-3 ± √21
x = -----------------
2
Answer:
-63
Step-by-step explanation:
Write the problem as a mathematical expression.

Simplify 4−4−8 to substitute in f(x)=−x^2+1
Subtract 4 from 4

Subtract 8 from 0

Replace the variable x with −
8 in the expression

Simplify


Answer = -63
Plz give me Brainliest if you can, hope this helps.
Answer:
420
Step-by-step explanation:
The number of students in the school is unknown, so we'll call it x.
55% of the number of students are girls.
There are 321 girls.
55% of x = 231
0.55x = 231
x = 231/0.55
x = 420
Answer: 420