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2 years ago

A car travels at an average speed of 80 km/h for 6 hours.

Mathematics

1 answer:

guapka [62]2 years ago

6 0

Answer:

63km/h

Step-by-step explanation:

devide 80 km/h over 6hrs and get 13 ... subtract 13 from 80 km/h and get 63 km/h

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The Symphony

lord [1]

Answer is 12.50. u can comment on my answer if you would like to see how that is the correct answer :)

5 0

3 years ago

A baker buys 19 apples of two different varieties to make pies. The total cost of the apples is $5.10. Granny Smith apples cost

Natasha2012 [34]

The baker bought 7 gala apples, and 12 granny smiths apples

Solution:

Let "x" be the number of gala apples bought

Let "y" be the number of granny smith apples bought

Cost of 1 gala apple = $ 0.30

Cost of 1 granny smith apple = $ 0.25

A baker buys 19 apples of two different varieties to make pies

Therefore,

number of gala apples bought + number of granny smith apples bought = 19

x + y = 19 --------- eqn 1

The total cost of the apples is $5.10

Therefore, we can frame a equation as:

number of gala apples bought x Cost of 1 gala apple + number of granny smith apples bought x Cost of 1 granny smith apple = 5.10

$x \times 0.30 + y \times 0.25 = 5.10$

0.3x + 0.25y = 5.1 -------- eqn 2

Let us solve eqn 1 and eqn 2

From eqn 1,

x = 19 - y ---------- eqn 3

Substitute eqn 3 in eqn 2

0.3(19 - y) + 0.25y = 5.1

5.7 - 0.3y + 0.25y = 5.1

5.7 - 0.05y = 5.1

0.05y = 5.7 - 5.1

0.05y = 0.6

y = 12

Substitute y = 12 in eqn 3

x = 19 - 12

x = 7

Thus the baker bought 7 gala apples, and 12 granny smiths apples

6 0

3 years ago

50 Points!

Advocard [28]

Well, 50 points total given, 25 points per user and 13 bonus for brainliest

anyway

1.
add them equations, the y's will cancel
x+2y=4
3x-2y=4 +
4x+0y=8

4x=8
divide by 4 both sides
x=2
sub back
x+2y=4
2+2y=4
minus 2
2y=2
divide 2
y=1
x=2
y=1
(x,y)
(2,1) is solution

2.
the solution is where they intersect
multiply 2nd equation by 2 and add to first
4x-14y=6
-4x+14y=-6 +
0x+0y=0
0=0
infinite solutions

that is because they are actually the same line
the solutions are (x,y) such that they satisfy -2x+7y=-3 or 4x-14y=6 (same equaiton)
infinite solutions

3.
multiply first equation by 2 and add to first
4x+2y=-6
1x-2y=-4 +
5x+0y=-10

5x=-10
divide by 5 both sides
x=-2
sub bac
x-2y=-4
-2-2y=-4
add 2
-2y=-2
divide by -2
y=1

x=-2
y=1
(x,y)
(-2,1)

4.
coincident means they are the same line
so

we see that we have to multiply 4 by 2 to get 8
multiply top equation by 2
8x+10y=16
8x+By=C
B=10 and C=16

5.
a. false, either 0, 1, or infinity solutions
change the word 'two' to 'one' or 'zero' or 'infinite', or change 'can' into 'can't'

b.false
'sometimes' to 'always'

c. true

d. false, change 'sometimes' to 'always'

EC
total cost=150
TC=childC+adultC
TC=3c+5a
150=3c+5a

40 tickets, c+a
40=c+a

the equations are
150=3c+5a and
40=c+a

eliminate
multiply 2nd equaton by -3 and ad to first one

150=3c+5a
-120=-3c-3a +
30=0c+2a

30=2a
divide by 2
15=a

sub back
40=c+a
40=c+15
minus 15
25=c

25 children tickets and 15 adult tickets were sold

ANSWERS:

1.
(2,1) is solution

2.
infinite solutions

3.
(-2,1)

4.
B=10 and C=16

5.
a. false,
change the word 'two' to 'one' or 'zero' or 'infinite', or change 'can' into 'can't'

b.false
'sometimes' to 'always'

c. true

d. false, change 'sometimes' to 'always'

EC
the equations are
150=3c+5a and
40=c+a
25 children tickets and 15 adult tickets were sold

7 0

3 years ago

Read 2 more answers

If y=-5 when x=2,find y when x=8

LenaWriter [7]

You can’t really know the y value unless you’re told that they’re both directly proportional. if so, then check out the pic