Đáp án:
Giải thích các bước giải:
a)y=f(x)=3x-8
f(3)=3.3-8=9-8=1
f(-2)=3.(-2)-8=-6-8=-14
b) tại y=1 ta có: f(x)=3x-8=1
⇔f(x)=3x=1+8=9
⇒x=3
chúc bạn học tốt
Exercise 5: Choose the best option to fill in the blank. 1. There used to be fewer people and .................. on the roads. A. roofs B. helmets C. helicopters D. vehicles 2. Do you know the .................. in the UK is to keep to the left? A. traffic light B. traffic rule C. traffic jam D. speed limit 3. It is dangerous to ride a motorbike without a .................. A. helmet B. triangle C. tricycle D. circle 4. In Hanoi, during rush hour, some road users ride their motorbikes on the .................. A. driving licence B. lane C. pavement D. seat belt 5. Traffic is terrible during the .................. when everyone is in a hurry to get to work or come back home. A. traffic light B. road sign C. traffic rule D. rush hour 6. The ................ for motorcycles is 40 km/h in towns and 60 km/h outside urban areas. A. speed limit B. driving licence C. traffic rule D. traffic light 7. You must .................. the traffic rules in order to avoid accidents. A. park B. obey C. reverse D. warn 8. It takes us more than three hours to drive across those .................. roads. A. wide B. safely C. right-handed D. bumpy 9. You need a driving licence to .................. A. drive a car B. ride a bike C. get on the bus D. get off the train 10. The large supermarkets in Vietnam often let you .................. free. A. park B. obey C. warn D. find 11. Some vehicles beep when they .................. to warn those behind. A. ride B. reverse C. drive D. sail 12. After school, children queue up and wait for the bus .................. on the pavement in front of the school. A. safe B. bumpy C. safety D. safely
Biết: $x^{}$ + $y^{}$ = -5 Và $xy^{}$ = 6 Tính: $(x^{3}+y^{3}+34)^{2019}$
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Mik hơi ngu về khoản này,m.n giúp mik với😅😅😅😅
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