Help 1: You answer 82% of the questions correctly on a 50-question test. How many questions do you answer incorrectly?

2: In a class, 60% of the students are girls. There are 21 girls in the class.
A: How many Students are in the class?
B: How many boys are in the class?

1: 9 questions incorrect and 41 correct

2: There are a total of 35 students. 21 girls and 14 boys.

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form

step-by-step explanation:

left be aligning the decimal points is required to not required see the number of digits to the right