10 you own a beauty salon where you not only cut hair but you also sell hair products. you buy a dozen barrettes for $18.00 and then sell them in your store for $2.00. you want to calculate your mark-up. to do so, you multiply 2 by 12, subtract 18 and then divide by 12. is this correct?
a) yes.
b) no; you should divide 18 by 12 and then divide by 2.
c) no; you should divide 18 by 12, divide by 2 and multiply by 100.
d) no; you should multiply 2 by 12, subtract 18 and then divide by 18.
*show your work

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