Question

1. sederhanakanlah
3(2a+7)+5a-15
2.jika panjang lahan pak tani 8 m, sedangkan lebarnya (x+5)m dan luasnya 120m persegi.
tentukanlah nilai x tersebut....

Answer 1

3(2a+7)+5a-15
=6a+21+5a-15
=6a+5a+21-15
=11a+6

Answer 2

1. 3(2a+7)+5a-5
= 6a+21+5a-15
= 6a+5a+21-15
= 11a+6

2. 8 x (x+5) = 120
= 8x + 40 = 120
= 8x = 120 - 40
8x = 80
x = 80/8
x = 10
Pembuktian :
8 x (10+5) = 120
8 x 15 = 120...... ok. semoga bermanfaat.