Which two points on the number line represent numbers that can be combined to make zero? CO
А
B
C D
-9-8-7-6-5-4-3 -2 -1 0 1 2 3 4
5 6 7 8 9
OB and D
O A and B
O C and D
O A and C

option (D) is the right answer

10 five-point questions and 40 two-point questions

Step-by-step explanation:

Let x represent the total number of five-point questions and y represent the total number of two-point questions.

Equation 1:     5x+2y=130

Equation 2:     x+y=50

Multiplying Equation 2 by 2:     2x+2y=100     (Equation 3)

(Equation 1) - (Equation 3):     3x=30

                                                  x=10

Substituting x=10 into x+y=50:     10+y=50

                                                            y=40

Therefore, there are 10 five-point questions and 40 two-point questions.

Substituting x=10 and y=40 into Equation 1:

LHS=5x+2y=5(10)+2(40)=50+80=130

RHS=130

LHS=RHS

Substituting x=10 and y=40 into Equation 2:

LHS=x+y=10+40=50

RHS=50

LHS=RHS

Since in both cases the left-hand side is equal to the right-hand side, the answer is correct.

(LHS: left-hand side, RHS: right-hand side)