Question

помогите, пожалуйста, с решениями уравнений

Answer 1

59.

$(5x-6)+(3x-40)=2\\\\5x-6+3x-40=2\\\\8x-46=2\\\\8x=48\\\\x=6$

60.

$(0.3x-5)-(9-0.4x)=7\\\\0.3x-5-9+0.4x=7\\\\0.7x-14=7\\\\0.7x=21\\\\x=30$

61.

$(1.2x+6)+(12-0.3x)=-9\\\\1.2x+6+12-0.3x=-9\\\\0.9x+18=-9\\\\0.9x=-27\\\\x=-30$

62.

$(2-6.1x)-(1.1x+6.4)=10\\\\2-6.1x-1.1x-6.4=10\\\\-7.2x-4.4=10\\\\-7.2x=14.4\\\\x=-2$

63.

$(0.3x+7)-(11-0.2x)=-17\\\\0.3x+7-11+0.2x=-17\\\\0.5x-4=-17\\\\0.5x=-13\\\\x=-26$

64.

$(2\frac{1}{7} x+3)-(1\frac{3}{14}x+8)=8\\\\\frac{15}{7} x+3-\frac{17}{14} x-8=8\\\\\frac{13}{14} x-5=8\\\\\frac{13}{14} x=13\\\\x=14$

65.

$(2x-6.4)(15-5x)=0\\\\2x-6.4=0\\\\2x=6.4\\\\x=3.2\\\\15-5x=0\\\\-5x=-15\\\\x=3$

66.

$(3x-6.9)(4.5-9x)=0\\\\3x-6.9=0\\\\3x=6.9\\\\x=2.3\\\\4.5-9x=0\\\\9x=4.5\\\\x=0.5$

11.

$(17a-12b-14c)-(11a-10b-14c)=17a-12b-14c-11a+10b+14c=\\\\=6a-2b=2(3a-b)$

12.

$(12a^{2} -7ab)-(3a^{2}-ab+b^{2})=12a^{2}-7ab-3a^{2}+ab-b^{2}=9a^{2}-6ab-b^{2}$

13.

$(x^{2} -x)-(x^{2} -2x+9)=x^{2}-x-x^{2}+2x-9=x-9$

14.

$(7x+8)-(2+6x)+(6+x+x^{2})=7x+8-2-6x+6+x+x^{2}=x^{2}+2x+12$

15.

$(12a^{2}+11c-8)-(14a-5c)=12a^{2}+11c-8-14a+5c=12a^{2}-14a+16c-8=\\\\=2(6a^{2}-7a+8c-4)$

16.

$(5a^{2}-10a+3)-(3-10a-5a^{2})=5a^{2}-10a+3-3+10a+5a^{2}=10a^{2}$