1.(2x^5+3x³+2x-4)-(7x⁴+3x²-5x+8) 2.(9x³+3x²-5x-4)+(-3x⁴-9x²+8x+1) 3.(27x⁴-7x+2x²-81)-(-90x⁴-15x²+100) 4.(x-7).(x⁴+5x³+8x-3x-7) 5.(x²+3x-4).(x³-5x²-3x+8) Tolong

No. 1
[tex]\left ( 2x^5+3x^3+2x-4 \right ) - \left ( 7x^4+3x^2-5x+8 \right ) \\ = 2x^5 - 7x^4 +3x^3 -3x^2 + (2 + 5)x - 8 \\ = 2x^5 - 7x^4 +3x^3 -3x^2 + 7x - 8 \\[/tex]

No. 2
[tex]\left ( 9x^3+3x^2-5x-4 \right ) + \left ( -3x^4-9x^2+8x+1 \right ) \\ = -3x^4 +9x^3 + (3-9)x^2 + (-5+8)x + (-4 + 1) \\ = -3x^4 +9x^3 - 6x^2 + 3x -3[/tex]

No. 3
[tex]\left ( 27x^4-7x+2x^2-81 \right ) - \left ( -90x^4-15x^2+100 \right ) \\ = (27+90)x^4 + (2+15)x^2 -7x + (-81-100) \\ = 117x^4 + 17x^2 - 7x -181[/tex]

No. 4
[tex]\left ( x-7 \right ) \left ( x^4+5x^3+8x-3x-7 \right ) \\ = \left ( x-7 \right ) \left ( x^4+5x^3+5x-7 \right ) \\ = \left ( x^5+5x^4+5x^2-7x \right ) + \left ( -7x^4-35x^3-35x+49 \right ) \\ = x^5 + (5-7)x^4 -35x^3 + 5x^2 + (-7 -35)x + 49 \\ = x^5 -2x^4 -35x^3 + 5x^2 - 42x + 49 \\[/tex]

No. 5
[tex]\left ( x^2+3x-4 \right ) \left ( x^3-5x^2-3x+8 \right ) \\ = \left ( x^5-5x^4-3x^3+8x^2 \right ) + \left ( 3x^4-15x^3-9x^2+24x \right ) \\ \text{} \quad + \left ( -4x^3+20x^2+12x-32\right ) \\ = x^5 + (-5+3)x^4 + (-3-15-4)x^3+ (8-9+20)x^2 \\ \text{} \quad + (24+12)x - 32\\ = x^5 -2x^4 -22x^3 +19x^2 + 36x - 32[/tex]