Vamos calcular quantos metros de corda Maria comprou na segunda vez:
33 - 21 = 12
Ela pagou R$ 9,60 a mais na segunda compra do que na primeira.
Logo, Maria pagou R$ 9,60 em 12 metros
Agora vamos calcular quanto ela pagou por metro:
9,60 ÷ 12 = 0,80
R$ 0,80 por metro
Para saber quanto Maria gastou na primeira compra multiplicamos os 21 metros pelo seu valor unitário:
21 × 0,8 = 16,80
Resposta: R$ 16,80 Letra B
Answer:
-3 ≤ x <-2
Step-by-step explanation:
First, you should set up the equation to solve it, which is,
21 ≤ -3(x-4)<18
Then you should simplify the equation to,
21 ≤ -3x+12<18
Then subtract 12 from both sides.
9 ≤ -3x<6
Lastly, divide -3 from both sides.
-3 ≤ x<-2
Take 25 and divide it by 38. 25/38= a decimal. Take and do the long division bridge, 25 on the iside and 38 on the outside. 38 does not go into 25 so you add a decimal point after the 25 and put a 0. now making the division equation 250/38 but dont forget to put aq decimal up top. Then you take 250/38 and you will get 6.57... but you will ormally roud the answer up so it would be .66
Answer:
50 black keys
Step-by-step explanation:
for every set of 7 white keys there are 5 black keys
72/7 = 10
so there is a total of 10 full sets of keys
then you have 2 white keys remaining but that doesn't matter because they will just be on the dies and already have a black key next
so this means that you only have to calculate the number of 10 sets of black keys and thats 5 x 10.
hope this helps : )
$90 because you take the discounted price then divide it by .40 (40%)
