Question

Putin ajutor ? 

4. $\frac{3a+7b}{5a+9b}= \frac{17}{23} atunci calculati \frac{a}{b}$

5. 0,45h + 57$dam^{2}$

6. Calculati: $1 \frac{1}{2}* \frac{8}{9} : 1 \frac{1}{3}-1$       Multumesc !

Answer 1

4)23(3a+7b) = 17(5a+9b)

69a +161b= 85a +153b

69a-85a=153b -161b

-16a = -8b |: (-2)

2a=b

a/b= 1/2

5)0,45ha= 4500m²
57dam²=5700m²

4500+5700=10 200m²

6)3/2 * 8/9  * 4/3  -1=

= 4/3 *4/3 -1=

=16/9-1=

=(16-9)/9=  7/9