Explanation:
Let the price of a toy car be a.
Let the price of a yo-yo be b.
You can solve this problem using simultaneous linear equation.
From the question above, you can form 2 separate equations.
For the first equation,
3 toy cars sold next day = 3a
12 yo-yos sold next day = 12b
Total price = $102
The second equation would be
[tex]3a + 12b = 102[/tex]
Now, we are not finished yet. Make sure that for the first equation, only one of the unknown (a or b) stays on the left-hand side of the equation. Let's try a.
[tex]3a + 12b = 102 \\ 3a = 102 - 12b \\ a = \frac{102 - 12b}{3} \\ a = 34 - 4b[/tex]
Lets move on with finding the second equation.
15 toy cars sold = 15a
20 yo-yos sold = 20b
Total price = $190
So, the second equation would be:
[tex]15a + 20b = 190[/tex]
You don't have to move any unknowns to the other side for the second equation.
Now, take equation 1 and substitute into equation 2. This can be done by replacing the value of a in the second equation with the value of a on the right hand-side of the first equation. For example:
[tex]15a + 20b = 190 \\ 15(34 - 4b) + 20b = 190 \\ 510 - 60b + 20b = 190 \\ 510 - 190 = 60b - 20b \\ 320 = 40b \\ b = \frac{320}{40} \\ = 8[/tex]
Hence, the price of a yo-yo, b, is $8. The price of a toy car is :
[tex]a = 34 - 4b \\ = 34 - 4(8) \\ = 2[/tex]
$2.
The cost of one toy car is $2.
Two or more linear equations that all contain the same unknown variables are called a system of simultaneous linear equations. Solving such a system means finding values for the unknown variables which satisfy all the equations at the same time.
Let the price of a toy car be [tex]a[/tex].
Let the price of a Yo-Yo be [tex]b[/tex].
For the first equation,
3 toy cars sold the next day = 3[tex]a[/tex]
12 yo-yos sold the next day = 12[tex]b[/tex]
Total price = $102
The first equation would be
3[tex]a[/tex]+12[tex]b[/tex]=102
Finding the second equation.
15 toy cars sold = 15[tex]a[/tex]
20 yo-yos sold = 20[tex]b[/tex]
Total price = $190
So, the second equation would be:
15[tex]a[/tex]+20[tex]b[/tex]=$190
With the help of these equations, we can find the price of a toy car.
Learn more about simultaneous linear equations here https://brainly.com/question/21766426
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