103. Решить уравнения: 1) 3x+5=17; 2) 5x+8=23; 3) 4+6x=16; 4) 2,4x+6,2=78,2; 5) \frac{3}{4}x+2=23; 6) 10x-4=2,6; 7) 15x-123=102; 8) 2x-8=1; 9) 35-5x = 20; 10) 52-7x = 31; 11) 15-3a = 3; 12) 8-6x = 5; 13) 4,8-4m = 1,6; 14) 5\frac{1}{2} - 2y = 1\frac{3}{4}.

Решим каждое уравнение пошагово: 1) $$3x + 5 = 17$$ $$3x = 17 - 5$$ $$3x = 12$$ $$x = \frac{12}{3}$$ $$x = 4$$ 2) $$5x + 8 = 23$$ $$5x = 23 - 8$$ $$5x = 15$$ $$x = \frac{15}{5}$$ $$x = 3$$ 3) $$4 + 6x = 16$$ $$6x = 16 - 4$$ $$6x = 12$$ $$x = \frac{12}{6}$$ $$x = 2$$ 4) $$2.4x + 6.2 = 78.2$$ $$2.4x = 78.2 - 6.2$$ $$2.4x = 72$$ $$x = \frac{72}{2.4}$$ $$x = 30$$ 5) $$\frac{3}{4}x + 2 = 23$$ $$\frac{3}{4}x = 23 - 2$$ $$\frac{3}{4}x = 21$$ $$x = 21 \cdot \frac{4}{3}$$ $$x = \frac{84}{3}$$ $$x = 28$$ 6) $$10x - 4 = 2.6$$ $$10x = 2.6 + 4$$ $$10x = 6.6$$ $$x = \frac{6.6}{10}$$ $$x = 0.66$$ 7) $$15x - 123 = 102$$ $$15x = 102 + 123$$ $$15x = 225$$ $$x = \frac{225}{15}$$ $$x = 15$$ 8) $$2x - 8 = 1$$ $$2x = 1 + 8$$ $$2x = 9$$ $$x = \frac{9}{2}$$ $$x = 4.5$$ 9) $$35 - 5x = 20$$ $$-5x = 20 - 35$$ $$-5x = -15$$ $$x = \frac{-15}{-5}$$ $$x = 3$$ 10) $$52 - 7x = 31$$ $$-7x = 31 - 52$$ $$-7x = -21$$ $$x = \frac{-21}{-7}$$ $$x = 3$$ 11) $$15 - 3a = 3$$ $$-3a = 3 - 15$$ $$-3a = -12$$ $$a = \frac{-12}{-3}$$ $$a = 4$$ 12) $$8 - 6x = 5$$ $$-6x = 5 - 8$$ $$-6x = -3$$ $$x = \frac{-3}{-6}$$ $$x = \frac{1}{2} = 0.5$$ 13) $$4.8 - 4m = 1.6$$ $$-4m = 1.6 - 4.8$$ $$-4m = -3.2$$ $$m = \frac{-3.2}{-4}$$ $$m = 0.8 $$ 14) $$5\frac{1}{2} - 2y = 1\frac{3}{4}$$ $$5.5 - 2y = 1.75$$ $$-2y = 1.75 - 5.5$$ $$-2y = -3.75$$ $$y = \frac{-3.75}{-2}$$ $$y = 1.875$$