Question 15 Marks
The value of the expression $(10 y-20)$ depends on the value of $y$. Verify this by giving five different values to $y$ and finding for each $y$ the value of $(10 y-20)$. From the different values of $(10 y-20)$ you obtain, do you see a solution to $10 y-20=50$ ?
If there is no solution, try giving more values to $y$ and find whether the condition $10 y-20=50$ is met.
If there is no solution, try giving more values to $y$ and find whether the condition $10 y-20=50$ is met.
Answer
View full question & answer→Let us find the value of the expression (10 y – 20) for different values of y.
Thus, the condition 10y - 20 = 50, is true for y =7.
Hence, y =7 is the solution of the equation 10y — 20.
| Value of y | Value of given expression ( 10 y-20 ) |
| When y=-1 | 10 x (-1)-20=-10-20=-30 |
| When y=0 | 10 x 0-20=0-20=-20 |
| When y=1 | 10 x 1-20=10-20=-10 |
| When y=2 | 10 x 2-20=20-20=0 |
| When y=3 | 10 x 3-20=30-20=10 |
| When y=4 | 10 x 4-20=40-20=20 |
| When y=5 | 10 x 5-20=50-20=30 |
| When y=6 | 10 x 6-20=60-20=40 |
| When y=7 | 10 x 7-20=70-20=50 |
Hence, y =7 is the solution of the equation 10y — 20.