

as you already know, a direct proportional variation has a constant of variation "k", y = kx, which in this case that'd be the slope, namely 15.
16 because 40-12=28 and Samad will be 28 on 16 years. In 16 years his father will be 56 which is double of 28.
45 would most likely be right
Answer:
12. -11
13. 2
Step-by-step explanation:
12. First recall the order of operations (BEDMAS): Brackets, Exponents, Division, Multiplication, Addition, Subtraction
For question 12 there is a division and its priority is before other operations in the equation so you must divide 16/-2 first which gives you -8.
From there because addition and subtraction is on the same level of order, you would do the question straight as it is shown (but replace 16/-2 with -8.
Your new equation is -10-8+7 = -11
13. follow the same as above using BEDMAS. It may help to look at it with additional brackets: ((-68)/(-4)) + ((5 x (-3))
- keep in mind there’s an addition between the two
Division and multiplication is on the same level in BEDMAS so first divide -68/-4 = 17
Second multiply 5 x -3 = -15
Now you can combine the two answers using addition: 17 + (-15) = 2