Tolong ka no 1,4,dan 5​

1.

a = -1

b = 4

c = 7

3c – 5b x 2a

= 3(7) – 5(4) x 2(-1)

= 21 – 20 x (-2)

= 21 – (-40)

= 21 + 40

= 61

4.

2,45 + 1 3/4 – 12% = E

2,45 + 1,75 – 0,12 = E

E = 4,08

5.

banyak permen yang diterima

= 8 x 42 : 16

= 336 : 16

= 21 butir permen