Math question:

Ann can swim 20 laps in 8 min. how long will it take to swim 9 laps? show your equations(s).

Volgvan

Take 20 laps divide by 8 then take the number times 9 laps

6 0

3 years ago

On a coordinate plane, a line goes through (negative 12, negative 2) and (0, negative 4). A point is at (0, 6).

mariarad [96]

Point (-12 , 8) is on the line that passes through (0, 6) and is parallel to the given line ⇒ 1st

Step-by-step explanation:

Parallel lines have:

Same slopes
Different y-intercepts

The formula of the slope of a line which passes through points $(x_{1},y_{1})$ and $(x_{1},y_{1})$ is $m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}$

∵ The given line passes through points (-12 , -2) and (0 , -4)

∴ $x_{1}$ = -12 , $x_{2}$ = 0

∴ $y_{1}$ = -2 , $y_{2}$ = -4

- Use the formula of the slope above to find the slope of the given line

∵ $m=\frac{-4-(-2)}{0-(-12)}=\frac{-4+2}{12}=\frac{-2}{12}=\frac{-1}{6}$

∴ The slope of the given line is $\frac{-1}{6}$

∵ The two lines are parallel

∴ Their slopes are equal

∴ The slope of the parallel line = $\frac{-1}{6}$

∵ The parallel line passes through point (0 , 6)

- The form of the linear equation is y = mx + b, where m is the slope

and b is the y-intercept (y when x = 0)

∵ m = $\frac{-1}{6}$ and b = 6

∴ The equation of the parallel line is y = $\frac{-1}{6}$ x + 6

Let us check which point is on the line by substitute the x in the equation by the x-coordinate of each point to find y, if y is equal the y-coordinate of the point, then the point is on the line

Point (-12 , 8)

∵ x = -12 and y = 8

∵ y = $\frac{-1}{6}$ (-12) + 6

∴ y = 2 + 6 = 8

- The value of y is equal the y-coordinate of the point

∴ Point (-12 , 8) is on the line

Point (-12 , 8) is on the line that passes through (0, 6) and is parallel to the given line

Learn more:

You can learn more about the equations of parallel lines in brainly.com/question/9527422

#LearnwithBrainly

4 0

3 years ago

Read 2 more answers

How to solve equations with the substitution method

Paul [167]

Answer:

In a system, the substitution method is one of the 3 main ways to solve a system and can be very efficient at times.

<u>Skills needed: Systems, Algebra</u>

Step-by-step explanation:

1) Let's say we are given two equations below:

$y=4x \\ 4x-5y=-32$

We can use substitution here by substituting in for $y$ in the second equation. This means we put in $4x$ for $y$ in the 2nd equation so we only have $x$ variables in the equation, allowing us to solve for $x$ .

2) Solving it out:

$1) 4x-5(4x)=-32 \\ 2) 4x-20x=-32 \\3) -16x=-32 \\4)x=2\\5)y=4x = 4(2) = 8 \\ 6)y=8$

We essentially substitute in that value as seen in step 1. Steps 2 and 3 are just simplifying the left side and allowing for us to solve. Step 4 is where we divide by -16 on both sides to solve for x. Step 5 and 6 show us solving for y using the value for x. We get $x=2,y=8$