A teacher had t packs of notebooks, with 7 notebooks in each. He distributed 3 packs among his students. How many notebooks does he have left?

7t-21

Step-by-step explanation:

In the beginning, the teacher has 7t notebooks. Since each pack if 7 notebooks, the teacher distributed 3*7=21 notebooks.

So, the teacher has 7t-21 notebooks left.

Hope this helps! :)

mxb67

step-by-step explanation:

step-by-step explanation:

y = | -2(-2) |     →     y = | 4 |     →     y = 4       ⇒   (-2, 4)

y = | -2(-1) |     →     y = | 2 |     →       y =   2       ⇒   (-1, 2)    

y = | -2(0) |     →     y = | 0 |     →       y = 0         ⇒   (0, 0)

y = | -2(1) |   c →     y = | -2 |     →     y =   2         ⇒   (1, 2)    

y = | -2(2) |     →     y = | - 4 |     →     y =   4         ⇒   (2, 4)