Antonette gets $70\%$ on a 10-problem test, $80\%$ on a 20-problem test and $90\%$ on a 30-problem test. if the three tests are combined into one 60-problem test, which percent is her overall score, rounded to the nearest percent?

Percentage score will be 83.33 %

Step-by-step explanation:

We have given Antonette gets 70 % on 10 problem test

Let consider here here total problem = total marks

So marks get 10 10 problem test = 10×0.7 = 7

Marks get in 20 problem test = 20×0.8 = 16

And marks get in 30 problem test = 30×0.9 = 27

Now total marks get get by Antonette = 7 +16 + 27 = 50

And total marks = 60

So percentage score of Antonette %

25.2

step-by-step explanation:

2+4x6-8/10= 25.2

(0,-3) see attached graph

step-by-step explanation:

a. to solve the system, graph the two equations.

x = y+3 becomes y=x-3 has m=1/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move up 1 unit and 1 unit to the right. plot a point and connect.

y=-4x+3 has m =-4/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move down four units and to the right 1 unit. plot a point and connect.

the solution is the point (x,y) where the two lines intersect. by the graph below it is (0,-3).

b. to solve by substitution, substitute y = -4x-3 into x= y+3

x= (-4x-3) +3

x=-4x

5x=0

x=0

now substitute x = 0 back in to find y.

y= -4(0)-3

y=0-3

y=-3

solution is (0,-3)

c. use elimination by adding the equations together.

x-y=3

4x+y=-3

5x=0

x=0

then substitute into one equation to find y.

y=-4(0)-3

y=-3