Question

Aplica la estrategia
7 x 40 =
8 x 50 =
14 x 20 =
5 x 90 =
​

Answer 1

13x-7

=

3x+233

-13x-3x

=

233+7

-16x

=

240

x

=

240/-16

x

=

-15

Comprobación

-13(-15)-7

=

3(-15)+233

195-7

=

-45+233

188

=

188

Ejercicio 2

13x+8

=

-14x-343

13x+14x

=

-343-8

27x

=

-351

x

=

-351/27

x

=

-13

Comprobación

13(-13)+8

=

-14(-13)-343

-169+8

=

182-343

-161

=

-161

Ejercicio 3

12x+1

=

-15x-404

12x+15x

=

-404-1

27x

=

-405

x

=

-405/27

x

=

-15

Comprobación

12(-15)+1

=

-15(-15)-404

-180+1

=

225-404

-179

=

-179

Ejercicio 4

-5x+9

=

12x+179

-5x-12x

=

179-9

-17x

=

170

x

=

170/-17

x

=

-10

Comprobación

-5(-10)+9

=

12(-10)+179

50+9

=

-120+179