Question

Determine a função do primeiro grau cujo gráfico passa pelos pontos A(0; -1) e B(1; 2)

Answer 1

$\tt a=\dfrac{y_B-y_A}{x_B-x_A}\\\tt a=\dfrac{2-(-1)}{1-0}\\\tt a=\dfrac{2+1}{1}=3\\\tt y=ax+b\\\tt-1=3\cdot0+b\\\tt b=-1\\\tt y=3x-1$