Question

Se der R$ 120,00 a cada menino, ficarei ainda com R$ 90,00. Para dar R$ 140,00 , faltar-me-ao R$ 210,00. Quanto são os meninos e Quanto possuo?​

Answer 1

• Faz uma equação de 1° grau

$\sf 15\cdot \:y\:-\:6\:=\:12\cdot \:y\:+\:60\:\\\\\\\sf 15y-6+6=12y+60+6\\\\\\\sf 15y=12y+66\\\\\\\sf 15y-12y=12y+66-12y\\\\\\\sf 3y=66\\\\\\\sf \dfrac{3y}{3}=\dfrac{66}{3}\\\\\\\boxed{\sf S=\{22 \}}$

Answer 2

⋅y−6=12⋅y+60

15y−6+6=12y+60+6

15y=12y+66

15y−12y=12y+66−12y

3y=66

3

3y

=

3

66

S={22}