Question

Calculeaza in scris si verifica dupa model.23×12?;31×13?;121×12?;212×14?;412×12?;131×13?.​

Answer 1

23*12=276
31*13=403
121*12=1.452
212*14=2.968
412*12=4.944
131*13=1.703

Answer 2

23×12=23×(10+2)
=23×10+23×2
=230+46
=276
31×13=31×(10+3)
=31×10+31×3
=310+93
=403
121×12=121×(10+2)
=121×10+121×2
=1210+242
=1452
212×14=212×(10+4)
=212×10+212×4
=2120+848
=2968
412×12=412×(10+2)
=412×10+412×2
=4120+824
=4944
131×13=131×(10+3)
=131×10+131×3
=1310+393
=1703