First column of (x) put {0,1,2,3,4} then substitute in the equation of y to get the y value for each x
then in each row you have (x,y) , so plot them on the graph and you will get a line
5x-3y=16
3x-5y=-4
Multiply the first equation by 3; the second one by 5
15x-9y=48
15x-25y=-20
Eq 1 - Eq 2:
-9y+25y=48+20=68
16y=68
4y=17
y=17/4
5x-3y=16
5x-3×17/4=16
5x=16+51/4=(64+51)/4=115/4
x=115/4/5=23/4
x=23/4
Answer:
4.3 hours
Step-by-step explanation:
Let the number of hours Sally does a job = x
Let the number did hours Joan does a job be equal to y
Sally and Joan were able to dust the house in 3 hours together.
1/x + 1/y = 1/3
It takes Joan 10 hours to finish the same job alone.
Hence,
1/x + 1/10 = 1/3
1/x = 1/3 - 1/10
Least common dey = 30
1/x = 10 - 3/30
1/x = 7/30
Cross Multiply
x × 7 = 30
7x = 30
x = 30/7
x = 4.2857142857 hours
Approximately = 4.3 hours
Without help, it would take Sally 4.3 hours to finish the same job.
We are given with two current costs : $3,450 for tables and $3,950 for chairs .The total cost then is equal to $7,400. This is said to be 4% more than he spent last year. so last year's expenses should be <span> $7,400 / 1.04 equal to $7115.39. The cost last year is expected to be less</span>