solve for the value of x encircle the letter of the correct answer
1.3×+18=63
a.5 b.10 c.15 d.20

2.1/2×-28=16+10
a.102 b.104 c.106 d.108

3.×-28=15+32
a.75 b.80 c.85 d.90

4.-108/×-15=27
a.9 b.-9 c.12 d.-12

5.6(2+×)=36
a.1 b.2 c.3 d.4​