Answers

  • Brainly User
2016-01-13T10:53:20+08:00
X + y = 23
y = 23 - x

Number of fruits:
x = oranges
y = apples  or  23-x = apples

Cost of fruits:
15 (x) = oranges
18 (23-x) = apples

Equation:
15 (x) + 18 (23-x) = 378
15x + 414 - 18x =  378
15x - 18x = 378 - 414
18x - 15x = 414 - 378
3x = 36
3x/3 = 36/3
x = 12

Substitute 12 to x in number of fruits:
Oranges: x = 12 
Apples: 23-12 = 11

ANSWER:  11 apples.

Check:
15 (12) + 18 (11) = 378
180 + 198 = 378
378 = 378

0
2016-01-13T17:32:03+08:00
Let x = no of oranges
23 - x = no. of apples

Cost of fruits:
15 (x) = oranges
18 (23-x) = apples

Equation:
15 (x) + 18 (23-x) = 378
15x + 414 - 18x =  378
15x - 18x = 378 - 414
18x - 15x = 414 - 378
3x = 36
 \frac{3x}{3} = \frac{36}{3}
x = 12

Substitute 12 to x in number of fruits:
Oranges: x = 12 
Apples: 23-12 = 11

Answer:  11 apples.

Check:
15 (12) + 18 (11) = 378
           180 + 198 = 378
                     378 = 378
0