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Murljashka [212]
3 years ago
15

If 3x + 5y = 42 and 9x +7y = 78, then x + y = ?

Mathematics
1 answer:
kumpel [21]3 years ago
8 0
3x+5y=42

9x+7y=78

adding above equation

12x+12y=120

x+y=10
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An investor invested a total of $2500 in two mutual funds. One fund earned a 5% profit while the other earned a 3% profit. If th
7nadin3 [17]

Answer:

$500 and $2000

Step-by-step explanation:

Let x represent the total investment = $2500

also, this total is split into two different funds

Lets represent these funds as a and b, such that fund a yields a profit of 3% and fund b yield a profit of 5%

So,

a + b = x

a + b =  2500   ......eq 1

Profit from each fund gives;

0.03 a + 0.05b = 115     ....eq 2

Solve simultaneously using substitution method

From eq 1;

b = 2500 - a

Slot in this value in eq 2

0.03a + 0.05 (2500 - a) = 115

expand

0.03a + 125 - 0.05a = 115

collect like terms

0.03a - 0.05a = 115 - 125

-0.02a = -10

Divide both sides by -0.02

a =  $500

Put this value of a in eq 1

500 + b =  2500

Subtract 500 from both sides

b = 2500 - 500

b = $2000

3 0
3 years ago
If joe travels 37 miles in 30 minutes, how far can he travel in 4 hours?
harkovskaia [24]

Answer:

296 miles

Step-by-step explanation:

4 hours=240 minutes

240/30=8

37*8=296

6 0
2 years ago
Read 2 more answers
Need help :)<br><br><br><br> pleaseeeeeee :(
gayaneshka [121]

Answer: x\geq 88

This means that he has to save at least $88 or more to have enough money.

Step-by-step explanation:

He has $37 and he needs to save more (+) but we don't know how much more that is, so that's why that is our unknown value. (x). The sum of them has to be at least 125 or greater.

37+x\geq 125

Subtract 37

x\geq125-37

x\geq 88

8 0
3 years ago
7.3 as a mixed number simlified
joja [24]
Answer: 7 3/10
seven as a whole number, and .3 equals to 3/10 when converted
8 0
2 years ago
2, 6, 10, 14, ...
8090 [49]

The sequence can be represented by 2 + 4x, where x is a whole number(x \geq 0 and x is an integer). By this, we should be able to plug in some whole number x and be able to get these values if they are in the sequence. To test this, let's set these numbers equal to 2 + 4x and confirm that there is a whole number x which equals the values selected.


2 + 4x = 90 \Rightarrow 4x = 88 \Rightarrow x = 22 \, \checkmark

2 + 4x = 150 \Rightarrow 4x = 148 \Rightarrow x = 37 \, \checkmark

2 + 4x = 160 \Rightarrow 4x = 158 \Rightarrow x = 39.5


When trying 160 with our equation, we find that x doesn't equal a whole number, thus our answer is C, or 160. To confirm our answer, we can test 170 and 210 and confirm that they both give us a value for x which is a whole number.


2 + 4x = 170 \Rightarrow 4x = 168 \Rightarrow x = 42 \, \checkmark

2 + 4x = 210 \Rightarrow 4x = 208 \Rightarrow x = 52 \, \checkmark

6 0
3 years ago
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