Hi people, if someone can give me a hand with this exponential functions problem. The sketch below shows part of the graph of y= ab^x where a and b are constants work out the value of a, b and k i found the values of a ( 4 ) and b which is = 6.25 but l cant find k if someone helps please thanks!

The price of an item has been reduced by 30%. the original price was $30. what is the price of the item now ?

Gabriel determined that his total cost would be represented by 2.5x + 2y – 2. his sister states that the expression should be x + x + 0.5x + y + y – 2. who is correct? explain.

Every weekday, mr. jones bikes from his home to his job. sometimes he rides along two roads, the long route that is shown by the solid lines. other times, he takes the shortcut shown by the dashed line. how many fewer kilometers does mr. jones bike when he takes the shortcut instead of the long route?