Respuesta :
Step-by-step explanation:
just put 4 in for x and see, if it works out.
7 - 4 = 12×4
3 = 48
no
4² + 3 = 10×4 - 21
16 + 3 = 40 - 21
19 = 19
yes
5 + 2×4 = 3×4 + 3
5 + 8 = 12 + 3
13 = 15
no
79 - 3×4 = 12×4 + 19
79 - 12 = 48 + 19
67 = 67
yes