, 28.10.2019 14:45 shannel99

# Atrain crosses a telegraph pole in 10sec. and a bridge with 255m long in 25sec find the length and speed of the train​

Length = (3a–5)cm

Perimeter = (16a–12)cm

Step-by-step explanation:

Area = Length x Width

(15a²–28a+5)cm² = (5a-1)cm x Length

Length = (15a²–28a+5)cm / (5a-1)

= (5a–1)(3a–5)cm / (5a-1)

Length = (3a–5)cm

Perimeter = Sum of the polygon's sides' measures

= Length + Width + Length + Width

= 2(Length + Width)

= 2[ (3a–5)cm + (5a-1)cm ]

= 2[ 3acm–5cm+5acm–cm ]

= 2[ 8acm–6cm ]

= 2[ 8a–6 ] cm

Perimeter = (16a–12)cm

tik tok kanalang

Step-by-step explanation:

Or mL nalang

Step-by-step explanation:

W = 5a + 1

Area = LW = 15a² + 28a + 5 cm

Missing: Length

Solution:

Factor the area

(5a + 1)(3a + 5)

Since W = 5a + 1;

Length must be = 3a + 5

Perimeter = 2L + 2W

= 2(3a+5) + 2(5a+1)

= 6a + 10 + 10a + 2

= 16a + 12

Length = 3a + 5 cm

Perimeter = 16a + 12 cm

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