Question

разложите на множители
а) (х-5)(2у-у)+(х-5)(4у+1)
б) (а-4)^2-(5а-4)

Answer 1

Ответ:

$(x - 5)(2y - y) + (x - 5)(4y + 1) = x \times 2y + x \times ( - y) - 5 \times 2y - 5 \times ( - y) + x \times 4y + x \times 1 - 5 \times 4y - 5 \times 1 = 2xy - xy - 10y + 5y + 4xy + x - 20y - 5 = 5xy - 25y + x - 5$

${(a - 4)}^{2} - (5a - 4) = {a}^{2} - 2 \times 4 \times a + {( - 4)}^{2} - 5a + 4 = {a}^{2} - 8a + 16 - 5a + 4 = {a}^{2} - 13a + 20$