Question

Ajutor imi trebuie si mie ex 11 si 15!​

Answer 1

11)

$a) \frac{5}{2} x + 3 = 10.75 \\ 2.5 \times x = 10.75 - 3 \\ 2.5 \times x = 7.75 \\ x = 7.75 \div 2.5 \\ x = 3.1$

$b)3 \times x - 2.7 = 1.11 \\ 3 \times x = 1.11 + 2.7 \\ 3 \times x = 3.81 \\ x = 3.81 \div 3 \\ x = 1.27$

$c)0.25 \times x + 1 = \frac{3}{2} \\ 0.25 \times x + 1 = 1.5 \\ 0.25 \times x = 1.5 - 1 \\ 0.25 \times x = 0.5 \\ x = 0.5 \times 0.25 \\ x = 0.125$

$d) \frac{1}{9} \times x - 3 = 5.25 \\ \frac{1}{9} \times \frac{x}{1} - \frac{3}{1} = \frac{5.25}{1} \\ \frac{1}{9} \times \frac{x}{1} = \frac{5.25}{1} + \frac{3}{1} \\ \frac{1}{9} \times \frac{x}{1} = \frac{8.25}{1} \\ \frac{x}{1} = \frac{8.25}{1} \div \frac{1}{9} \\ \frac{x}{1} = \frac{8.25}{1} \times \frac{9}{1} \\ \frac{x}{1} = \frac{74.25}{1} = > x = 74.25$

Answer 2

$\it a)\ \dfrac{5}{2}x+3=10,75|_{-3} \Rightarrow \dfrac{5}{2}x=7,75|_{\cdot2} \Rightarrow 5x=15,5|_{:5} \Rightarrow x=3,1\\ \\ \\ b)\ 3x-2,7=1,11|_{+2,7} \Rightarrow 3x=3,81|_{:3} \Rightarrow x=1,27\\ \\ \\ c)\ 0,25x+1=\dfrac{3}{2}\Rightarrow 0,25x+1=1,5|_{-1} \Rightarrow 0,25x=0,5|_{\cdot4} \Rightarrow x=2$

$\it d)\ \dfrac{1}{9}x-3=5,25|_{+3} \Rightarrow \dfrac{1}{9}x=8,25|_{\cdot9} \Rightarrow x=74,25$