The cost of bottles of vitamins varies directly with the number of vitamin
tablets in a bottle. A bottle of 50 vitamin
tablets costs $12. What is the cost in
dollars of a bottle of 75 vitamin tablets?

find cost of one vitamin tablet first

50/12 = 4.2

therefore $4.2 is the cost for one tablet

now to find the cost of 75 vitamin tablets we just need to multiply the cost of one tablet with 75.

75*4.2=315

therefore the cost of a bottle of 75 vitamin tablets is $315

70.30

step-by-step explanation:

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