If anyone could help me with this I'd be really grateful.

A is the point of coordinates (4,6)

B is the point with coordinates (d,21)

The gradient of the line AB is 3

Work out the value of D

Please provide a explanation

What’s the question here? what have you been learning about?

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)