How do you do this? can someone explain or with the answer? 41 43 45

There is a very great website called Desmos that can efficiently graph any equation. 

For 41, you can see that the function is negative which will then be an upside-down parabola.Inside the parentheses is x-1 which means that the entire parabola moves 1 unit to the right. (graph is attached)

For 43,  The function is half of a parabola with the vertex starting at the y-axis. The function will start at y=3 with a curve moving downwards since it's a negative function. (graph attached)

For 45, the function is a shape v and since it's a negative it will become an upside down v. x is added by 2 and the entire function is added by 3 which will mean the function will move 2 units to the left and 3 units up.

Hope This Helps :)

38+105= 143, 39+104=143, and you will find then adding the numbers on opposite sides, moving inwards yields the answer 138 every time. because of this, you’re going to multiply 138 times the number of pairs, which is 34. therefore, 34*138= 4692(i’m sorry if it’s the wrong numbers, but it’s the right concept)