Tính
a)x – 7x³ – x + 5 – x³ – 6
b) 10 – 12
c) -6 – 11
d) 7 – 10 – 12
e) -8x + 15x
f) 6x – 8y – 11x – 9y
g)6x³y² – 15x³y²
…) 4x – x² + 2 – 3x² – 6x – 7
Tính a)x – 7x³ – x + 5 – x³ – 6 b) 10 – 12 c) -6 – 11 d) 7 – 10 – 12 e) -8x + 15x f) 6x – 8y – 11x – 9y g)6x³y² – 15x³y² …) 4x – x² + 2 – 3x² – 6x –
By Maya
Đáp án:
a, Ta có
` x – 7x³ – x + 5 – x³ – 6`
` = (x – x) – (7x^3 + x^3) – (6 – 5)`
` = -8x^3 – 1`
b, `10 – 12 = -2`
c, `-6 – 11 = -17`
d, ` 7 – 10 – 12 = -15`
e, `-8x + 15x = 7x`
f,` 6x – 8y – 11x – 9y`
` = (6x – 11x) – (8y + 9y)`
` = -5x – 17y`
g, `6x^3y^2 – 15x^3y^2 = -9x^3y^2`
h, `4x – x^2 + 2 – 3x^2 – 6x – 7`
` = (4x – 6x) – (x^2 + 3x^2) – (7 – 2)`
` = -2x – 4x^2 – 5`
Giải thích các bước giải:
` a) ` ` x – 7x^3 – x + 5 – x^3 – 6 `
` = -7x^3 – x^3 + x – x + 5 – 6 `
` = -8x^3 – 1 `
` b) ` ` 10 – 12 = -2 `
` c) ` ` -6 – 11 = -17 `
` d) ` ` 7 – 10 – 12 = -15 `
` e) ` ` -8x + 15x = 7x `
` f) ` ` 6x – 8y – 11x – 9y `
` = 6x – 11x – 8y – 9y `
` = -5x – 17y `
` g) ` ` 6x^{3}y^{2} – 15x^{3}y^{2} `
` = -9x^{3}y^{2} `
` h) ` ` 4x – x^{2} + 2 – 3x^{2} – 6x – 7 `
` = -x^{2} – 3x^{2} + 4x – 6x + 2 – 7 `
` = -4x^{2} – 2x – 5 `