I will give brainliest answer for someone to answer this and no links just an answer
2 answers:
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Answer:
It would take them 6.667 minutes to paint 50 square feet together.
Step-by-step explanation:
This is a classic work problem. If Sam can do the job in 10 minutes, she can get done 1/10 of the job in one minute. If you can do the job in 5 minutes, you can 1/5 of the job done in one minute. To find out how many minutes it will take them together to paint 25 square feet, set the addition of their times equal to 1/x:
x is how long it takes them to get the job done together. Find the common denominator and multiply it through be everything to get rid of the denominators altogether. That denominator is 10x:
Simplify to get the simple equation x + 2x = 10 and 3x = 10. That means that x=3 1/3. That's how long it takes to do 25 square feet. Double that time for 50 square feet.
Answer:
The graph of the system of equations solves the equation x + 2 = 2x - 7 ⇒ C
Step-by-step explanation:
<em>Let us revise some important notes about the slope and y-intercept of a line</em>
The form of the linear equation is y = m x + b, where m is the slope and b is the y-intercept
- If the line has a positive slope then its direction will be to the right
- If the line has a negative slope then its direction will be to the left
The y-intercept (0, b) is the the point of intersection between the line and the y-axis
- If the line cuts the y-axis at a point above the x-axis, then b is positive
- If the line cuts the y-axis at a point down the x-axis, then b is negative
<em>To solve our question without any calculation, let us find the direction of the slopes and their y-intercepts</em>
∵ The direction of the blue line is to the left
→ That means m in the equation is negative
∴ Its slope is negative
∵ The line intersects the y-axis at point (0, 2)
→ That means b in the equation = 2
∴ The number in the equation is 2
→ Look at the answer we have two answers have negative slope and
y-intercept 2 in the left hand side ⇒ C and D
∴ The equation of the blue line is represented by the left side x + 2
→ that means the equation of the red line is represented by the right side
∵ The direction of the red line is to the right
→ That means m in the equation is positive
∴ Its slope is positive
→ Only C has a positive slope in the right side
∴ The equation of the red line is represented by 2x - 7
The graph of the system of equations solves the equation x + 2 = 2x - 7
<u><em>Another way:</em></u>
<em>You can solve each equation to find the value of x, then substitute it in one side of the equation to find y , the values of x and y must be (4, 1) as the point of intersection of the two lines in the graph</em>
Answer:
multiply the left side of the constant vector by the inverse matrix
Step-by-step explanation:
The matrix equation ...
AX = B
is solved by left-multiplying by the inverse of A:
A⁻¹AX = A⁻¹B
IX = A⁻¹B . . . . . the result of multiplying A⁻¹A is the identity matrix
X = A⁻¹B . . . . . B needs to be multiplied by the inverse matrix